Phytosulfokine and other small peptides deliver signals about growth and development in plants.
Nerve axons are insulated and protected by a sheath of myelin
Coronavirus spike protein binds to receptors on cell surfaces, and is a target for vaccine development.
Cryoelectron microscropy is revealing how spliceosomes cut-and-paste messenger RNA molecules.
Light is captured by huge supercomplexes of photosystems and antenna systems.
|Voltage-gated Sodium Channels|
Voltage-gated sodium channels transmit signals in a wave through the nervous system.
Coronavirus proteases are attractive targets for the design of antiviral drugs.
|Twenty Years of Molecules|
Celebrating the structural biology revolution
HIF-α is a molecular switch that responds to changing oxygen levels.
Phospholipase A2 breaks membrane lipids, forming molecules that contribute to inflammation and pain signaling.
Ribonucleotide reductase creates the building blocks of DNA
|Nanodiscs and HDL|
Nanodiscs conveniently package a small piece of membrane for experimental studies.
|Cyclin and Cyclin-dependent Kinase|
Cyclins and cyclin-dependent kinases control when cells divide, making them important targets for cancer therapy.
Receptors for the neurotransmitter glutamate in our brain come in several shapes and sizes.
|MDM2 and Cancer|
MDM2 controls the action of p53 tumor suppressor, making it a target for cancer chemotherapy.
Nitric oxide is attached to a conserved cysteine in hemoglobin and then released to control the flow of blood.
|Proteins and Biominerals|
Small biomineral crystals are used to build bone, eggshells and even tiny compasses.
|Measles Virus Proteins|
Six proteins in measles virus work together to infect cells.
|Initiation Factor eIF4E|
Initiation factors for protein synthesis interact through disordered chains.
|Fluorescent RNA Aptamers|
RNA aptamers are being engineered to track molecules inside living cells
|Directed Evolution of Enzymes|
Biological evolution is being harnessed in the lab to create new enzymes.
Telomerase maintains the ends of our chromosomes.
|Aminoglycoside Antibiotics and Resistance|
Bacteria become resistant to aminoglycosides by destroying them or changing their target.
Phytase is used in agriculture to mobilize indigestible phosphate compounds in livestock feed.
Legumain cleaves proteins, and can also put them back together.
|Piezo1 Mechanosensitive Channel|
Mechanosensitive ion channels give our cells a sense of touch.
|Proteins and Nanoparticles|
Nanotech scientists are designing new ways to combine proteins and nanoparticles
|Human Papillomavirus and Vaccines|
The capsid protein of papillomavirus is used in vaccines that prevent cervical cancer.
Bacteria destroy toxic environmental pollutants that include chlorine or bromine atoms.
Two linked molecular motors are used to pump protons across membranes.
|EPSP Synthase and Weedkillers|
The weedkiller Roundup attacks a key enzyme involved in the construction of aromatic compounds.
Morphine and other opioid drugs bind to receptors in the nervous system, controlling pain
Bacteria build biodegradable plastic that could be better for the environment
Key biosynthetic enzymes are regulated by their ultimate products through allosteric motions.
|Chimeric Antigen Receptors|
T cells may be engineered with chimeric antigen receptors to attack cancer cells.
Sirtuin activation is being explored as a way to slow aging.
Glutathione transferase tags toxic molecules, making them easy to recognize and remove.
A molecular machine with a rotary motor builds a long protein filament involved in bacterial motility and attachment.
|Adenine Riboswitch in Action|
XFEL serial crystallography reveals what happens when adenine binds to a riboswitch
|Tissue Transglutaminase and Celiac Disease|
Tissue transglutaminase staples proteins together by forming a chemical crosslink.
Glucose transporters deliver glucose molecules one-by-one across cell membranes.
|Photoactive Yellow Protein|
Researchers use synchrotrons and X-ray lasers to reveal the rapid processes of light sensing.
The mechanisms of molecular evolution are revealed in globin sequences and structures.
|Nuclear Pore Complex|
The nuclear pore complex is the gateway between the nucleus and cytoplasm.
|PD-1 (Programmed Cell Death Protein 1)|
PD-1 and its ligands are a new target for cancer therapy
|Aminopeptidase 1 and Autophagy|
Aminopeptidase 1 is delivered inside the cell using the machinery of autophagy
|Dipeptidyl Peptidase 4|
Inhibitors of dipeptidyl peptidase 4 are used to treat type-2 diabetes
Plants release a billion metric tons of isoprene and other organic gases every year.
|Quasisymmetry in Icosahedral Viruses|
Viruses use quasisymmetry to build large capsids out of many small subunits
Monellin and other supersweet proteins trick our taste receptors.
Beta-galactosidase is a powerful tool for genetic engineering of bacteria
Cryo-electron microscopy reveals the structure of Zika virus
Lead ions poison proteins throughout the body, blocking their normal function.
|RAF Protein Kinases|
A single mutation in a RAF protein kinase can help transform a normal cell into a cancer cell.
Engineered insulins have been developed to improve treatment of diabetes
Our innate immune system starves bacteria of iron using siderocalin.
The antibiotic vancomycin blocks the construction of bacterial cell walls.
|Glutamate-gated Chloride Receptors|
The antibiotic ivermectin attacks glutamate-gated chloride channels, paralyzing parasitic worms.
Bacteria respond to their environment with two-component sensing systems.
Alzheimer's disease and prion diseases are linked to unnatural aggregation of proteins into amyloid fibrils.
Tetrahydrobiopterin plays an essential role in the production of aromatic amino acids, neurotransmitters and nitric oxide.
|New Delhi Metallo-Beta-Lactamase|
Antibiotics can save lives, but antibiotic-resistant strains of bacteria pose a dangerous threat
|Receptor for Advanced Glycation End Products|
RAGE recognizes sugar-modified proteins, contributing to an inflammatory response that plays a role in diabetes
The giant protein titin organizes the structure of muscle and gives them elasticity
Glucagon triggers the release of glucose into the blood, to power cells throughout the body
Phototrophins sense the level of blue light, allowing plants to respond to changing environmental conditions
The cellular receptor for insulin helps control the utilization of glucose by cells
|Cascade and CRISPR|
Cascade and CRISPR help bacteria remember how to fight viral infection
TAL-effectors are modular, DNA-reading proteins that can be used to edit DNA in living cells
|Methyl-coenzyme M Reductase|
Methanogens use sophisticated molecular tools to build methane
|Ebola Virus Proteins|
Structures of ebola virus proteins are giving new hope for fighting this deadly virus
Apoptosomes make life or death decisions in cells
The motor protein dynein transports cellular cargo along microtubules
The largest filaments of the cytoskeleton provide tracks for transport throughout the cell
GFP-like proteins found in nature or engineered in the laboratory now span every color of the rainbow
Aquaporins create a channel for water molecules to cross through cell membranes
|RecA and Rad51|
Broken DNA strands may be repaired by matching sequences in a duplicate copy of the DNA
Neurotransmitters are transported out of nerve synapses to end a signal transmission
|Broadly Neutralizing Antibodies|
Structural studies of broadly neutralizing antibodies are paving the way to vaccines for HIV, influenza and RSV
|HIV Envelope Glycoprotein|
Envelope protein attaches HIV to the cells that it infects and powers fusion of the virus with the cell membrane
DNA helicase pries apart the two strands in a DNA double helix, powered by ATP
SNARE proteins power the fusion of vesicles with membranes by forming a bundle of alpha helices
Proteasomes destroy damaged or obsolete proteins inside cells
|Designed Protein Cages|
Researchers are modifying natural proteins to design new self-assembling protein cages
Serotonin receptors control mood, emotion, and many other behaviors, and are targets for many important drugs
At the center of HIV, an unusual cone-shaped capsid protects the viral genome and delivers it into infected cells
Small toxic peptides help protect us from bacterial infection
The structure of ricin reveals how it kills cells and how vaccines can produce immunity against ricin poisoning
Some antibiotics attack cells by intercalating between the bases in a DNA double helix
Earthworms build a huge version of hemoglobin to carry oxygen
|Proton-Gated Urea Channel|
A channel that passes urea allows ulcer-producing bacteria to live in the stomach
tmRNA rescues ribosomes that are stalled by damaged messenger RNA
|ABO Blood Type Glycosyltransferases|
ABO blood types are determined by an enzyme that attaches sugars to proteins
|Vitamin D Receptor|
Vitamin D helps regulate the use of calcium throughout the body
|Citric Acid Cycle|
Eight enzymes form a cyclic pathway for energy production and biosynthesis
|Pyruvate Dehydrogenase Complex|
A huge molecular complex links three sequential reactions for energy production
|cAMP-dependent Protein Kinase (PKA)|
PKA delivers cellular signals by adding phosphates to proteins
|Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)|
Cells salvage and recycle their obsolete DNA and RNA
Sliding clamps slide along DNA strands and keep DNA polymerase on track during replication
Problems with the appetite-controlling hormone leptin can lead to obesity
Mutation of the growth-contolling ras protein can lead to cancer
In our eyes, rhodopsin uses the molecule retinal to see light
Antibiotic-resistant bacteria build enzymes that destroy drugs like streptomycin
|Messenger RNA Capping|
Messenger RNA molecules are capped with an inverted nucleotide
A proton-pumping protein complex performs the first step of the respiratory electron transport chain
Toll-like receptors warn us about bacterial and viral infection
A dozen historic structures set the foundation for the PDB archive
Some protein functions are regulated when sugars are attached
|Rhomboid Protease GlpG|
Some proteases cut proteins embedded in cell membranes
Cells add methyl groups to their DNA to encode additional epigenetic information
Bacteria adhere to our teeth by building sticky sugar chains
A flow of electrons powers proton pumps in cellular respiration and photosynthesis
Unusual antibodies from camels are useful in research and medicine
HIV integrase allows HIV to insert itself into the genome of an infected cell
Integrins forge flexible linkages between the infrastructure inside and outside of cells
|Nitric Oxide Synthase|
Nitric oxide gas is used as a rapid-acting hormone and as a powerful defense
Adenovirus has an icosahedral capsid with unusual cell-binding fibers
Inteins splice themselves out of larger protein chains
Special sequences of messenger RNA can bind to regulatory molecules and affect synthesis of proteins
Atomic structures have revealed the catalytic steps of a citric acid cycle enzyme
Interferons mobilize defenses against viral infection
A concentrated solution of crystallins refracts light in our eye lens
|Epidermal Growth Factor|
EGF is part of a family of proteins that controls aspects of cell growth and development
Viruses that cause distemper are surrounded by an icosahedral capsid
|Concanavalin A and Circular Permutation|
For some proteins, clipped and reassembled sequences can produce the same 3D shape
P-glycoprotein pumps toxic molecules out of our cells
Enhanceosomes help decide the appropriate time to transcribe a gene
Ribosomes are complex molecular machines that build proteins
Small antifreeze proteins protect cells from damage by ice
|Designed DNA Crystal|
Small pieces of DNA have been engineered to form a nanoscale lattice
Cells continually pump sodium ions out and potassium ions in, powered by ATP
Xanthine oxidoreductase helps break down obsolete purine nucleotides
Sulfotransferases transfer sulfuryl groups in enzymatic reactions
Beta-secretase trims proteins in the cell and plays an important role in Alzheimer's disease
Cells build huge vault containers constructed of a symmetric arrangement of many subunits
Neuraminidase is an important target for influenza drugs
|Oct and Sox Transcription Factors|
Transcription factors decide when particular genes will be transcribed
Hydrogenases use unusual metal ions to split hydrogen gas
|Auxin and TIR1 Ubiquitin Ligase|
The plant hormone auxin controls growth and response to light and gravity
|Tobacco Mosaic Virus|
A cylindrical arrangement of proteins protects a long strand of RNA in TMV
Heat shock proteins ensure that proteins remain folded and active under harsh conditions
Pressure-sensitive channels open when the internal pressure of a cell gets too high
Poly(A) polymerase adds a long tail of adenine nucleotides at the end of messenger RNA
Ribonuclease cuts and controls RNA
Selenium is used in place of sulfur to build proteins for special tasks
Atomic structures of dengue virus are giving new hope for creation of a vaccine
Our cells temporarily build lactate when supplies of oxygen are low
Mad cow disease is caused by prion proteins that misfold and aggregate
Adrenaline stimulates a G-protein-coupled receptor, priming us for action
Adhesive cadherin proteins hold neighboring cells together
|Small Interfering RNA (siRNA)|
Our cells continually look for pieces of double-stranded RNA, a possible sign of viral infection
|Circadian Clock Proteins|
Circadian clock proteins measure time in our cells
Oxidosqualine cyclase forms the unusual fused rings of cholesterol molecules
|Multidrug Resistance Transporters|
Many bacteria use multidrug resistance transporters to pump drugs and poisons out of the cell
Superoxide dismutase protects us from dangerously reactive forms of oxygen
Citrate synthase opens and closes around its substrates as part of the citric acid cycle
Anabolic steroids like testosterone are among the most common performance enhancing drugs
Ultraviolet light damages our DNA, but our cells have ways to correct the damage
|Fatty Acid Synthase|
Fatty acids are constructed in many sequential steps by a large protein complex
|Aconitase and Iron Regulatory Protein 1|
Aconitase performs a reaction in the citric acid cycle, and moonlights as a regulatory protein
Three-armed clathrin triskelions are used to build molecular cages involved in transport
Zinc ions are used to strengthen small protein modules that recognize DNA
Exosomes destroy messenger RNA molecules after they have finished their jobs
Importins deliver proteins into the nucleus through the nuclear pore complex
Transposases shift genes around in the genome
Rod-shaped fibrin molecules link together to form blood clots
Cytochrome p450 detoxifies and solubilizes drugs and poisons by modifying them with oxygen
Protein synthesis requires the assistance of several elongation factors that guide each step
AAA+ proteases are ATP-powered molecular motors that thread protein chains through a hole
|Amyloid-beta Precursor Protein|
Cell-clogging amyloids form when proteins improperly aggregate
Organisms from fireflies to bacteria use luciferase to emit light
Glucose oxidase measures blood glucose level in biosensors
Influenza virus binds to cells and infects them using hemagglutinin
Tissue factor senses damage to the body and triggers formation of a blood clot
Amylases digest starch to produce glucose
Topoisomerases untangle and reduce the tension of DNA strands in the cell
ATP synthase links two rotary motors to generate ATP
The neurotransmitter acetylcholine opens a protein channel, stimulating muscle contraction
Researchers have successfully designed entirely new proteins based on biological principles
Many bacterial toxins have two parts: one that finds a cell, the other that kills it
Neurotrophins guide the development of the nervous system
TATA protein tells RNA polymerase where to get started on a gene
Light-sensing retinal molecules are built from colorful carotenoids in our diet
Special sequences of RNA are able to splice themselves
The motor protein kinesin carries cellular cargo along microtubules
Lymphocytes use T-cell receptors to patrol the body for foreign molecules
|Major Histocompatibility Complex|
MHC displays peptides on the surfaces of cells, allowing the immune system to sense the infection inside
An unusual cofactor is used in the synthesis of aromatic amino acids
Ubiquitin is used to tag obsolete proteins for destruction
Photosystem II captures the energy from sunlight and uses it to extract electrons from water molecules
Trimeric G-proteins receive signals from cellular receptors and deliver them inside the cell
Catalase protects us from dangerous reactive oxidizing molecules
Caspases disassemble proteins during the process of programmed cell death
DNA ligase reconnects broken DNA strands, and is used to engineer recombinant DNA
Acetylcholinesterase stops the signal between a nerve cell and a muscle cell
Serpins are traps that capture dangerous proteases
Growth hormone brings together two copies of its cellular receptor
Atomic structures have captured the calcium pump in action
The ten enzymes of glycolysis break down sugar in our diet
Carbonic anhydrase solubilizes carbon dioxide gas so we can breathe it out
|Catabolite Activator Protein|
CAP senses the level of sugar and mobilizes the proteins needed to utilize it
|Simian Virus 40|
SV40 hijacks the cells it infects using only a handful of proteins
An activated serine amino acid in trypsin cleaves protein chains
Estrogen binds to receptors in the nucleus and affects key genes in development
Calcium ions rapidly deliver signals to control processes such as muscle contraction, nerve signaling, and fertilization
|Src Tyrosine Kinase|
Growth signaling proteins play an important role in the development of cancer
|Green Fluorescent Protein (GFP)|
A tiny fluorescent protein from jellyfish has revolutionized cell biology
Hemoglobin uses a change in shape to increase the efficiency of oxygen transport
RNA polymerase transcribes genetic information from DNA into RNA
A genetic circuit controls the production of lactose-utilizing enzymes in bacteria
Potassium channels allow potassium ions to pass, but block smaller sodium ions
Serum albumin delivers fatty acid molecules through the bloodstream
Cytochrome c shuttles electrons during the production of cellular energy
|Ferritin and Transferrin|
Ferritin and transferrin manage our essential stores of iron ions
DHFR is a target for cancer chemotherapy and bacterial infection
|HIV Reverse Transcriptase|
HIV builds a DNA copy of its RNA genome, providing a unique target for drug therapy
Chaperones help new proteins fold into their proper shape
|p53 Tumor Suppressor|
p53 tumor suppressor protects the body from DNA damage and cancer
Glutamine synthetase monitors the levels of nitrogen-rich amino acids and decides when to make more
Penicillin attacks the proteins that build bacterial cell walls
Anthrax bacteria build a deadly three-part toxin
Bacteriorhodopsin pumps protons powered by green sunlight
Nitrogenase uses an exotic cluster of metals to fix atmospheric nitrogen into bioavailable ammonia
Thrombin activates the molecule that forms blood clots
Glycogen phosphorylase releases sugar from its cellular storehouse
Atomic structures reveal how the iconic double helix encodes genomic information
Photosystem I captures the energy in sunlight
Antibodies search for foreign molecules in the blood
|Poliovirus and Rhinovirus|
Crystallographic structures reveal the atomic details of viruses and how to fight them
Cells are supported by a cytoskeleton of protein filaments
Molecular motors fueled by ATP power the contraction of muscles
Aspirin attacks an important enzyme in pain signaling and blood clotting
Aminoacyl-tRNA synthetases ensure that the proper amino acids are used to build proteins
Transfer RNA translates the language of the genome into the language of proteins
The hormone insulin helps control the level of glucose in the blood
Alcohol dehydrogenase detoxifies the ethanol we drink
Pepsin digests proteins in strong stomach acid
Rubisco fixes atmospheric carbon dioxide into bioavailable sugar molecules
Atomic structures of the ribosomal subunits reveal a central role for RNA in protein synthesis
Lysozyme attacks the cell walls of bacteria
Bacterial enzymes that cut DNA are useful tools for genetic engineering
The cell's genome is stored and protected by nucleosomes
Atomic structures of HIV protease have been used to design powerful drugs for HIV therapy
|Cytochrome c Oxidase|
Cytochrome oxidase extracts energy from food using oxygen
Sturdy fibers of collagen give structure to our bodies
DNA polymerase makes an accurate copy of the cell's genome
Bacteriophage phiX174 hijacks bacterial cells and forces them to make new copies of the virus
Myoglobin was the first protein to have its atomic structure determined, revealing how it stores oxygen in muscle cells.