List of types of proteins

Proteins with unknown functions can sometimes be categorized according to their structural features if they contain a recognizable protein domainent .

• See Protein domains.

If the only thing known about a protein is the organism that produces it, then it can enjoy (as a last resort) being categorized according to the organism.

• Root NCBI Taxonomy Browser [3]
• WikiSpecies taxonomy system [4]

"The part of a cell of which a gene product is a component; for purpose of GO includes the extracellular environment of cells; a gene product may be a component of one or more parts of a cell; this term includes gene products that are parts of macromolecular complexes, by the definition that all members of a complex normally copurify under all except extreme conditions."

"Used as a holding place for cellular components whose precise localization is, as yet, unknown, or has not been determined by GO (the latter is the major reason for nodes to have this parent); this term should not be used for annotation of gene products." See also the cellular component term 'cellular component unknown’ (below).

"Used for the annotation of gene products whose localization is not known or cannot be inferred." Consider placing such proteins in Structural categories or organism categories

"The basic structural and functional unit of all organisms. Includes the plasma membrane and any external encapsulating structures such as the cell wall and cell envelope."

"The external part of the cell wall and/or cell membrane."
comment: Note that this term is intended to annotate gene products that are attached to the plasma membrane or cell wall.

2 types of membrane proteins are "integral" (such as ion channels) and "peripheral"

exact_synonym: "protoplasm"
"The living contents of a cell; the matter contained within (but not including) the plasma membrane, usually taken to exclude large vacuoles and masses of secretory or ingested material. In eukaryotes it includes the nucleus and cytoplasm."
See the Organelles category of Wikipedia.

"All of the contents of a cell excluding the plasma membrane and nucleus."

"A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent."

exact synonym: "membrane organelle"
"Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins."
See the Membrane biology category of Wikipedia.
See the Membrane proteins category of Wikipedia.
See the Integral membrane proteins category of Wikipedia.

"A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information."

exact_synonym: "extracellular"
Note that this term is intended to annotate gene products that are not attached to the cell surface.
"The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite."

"A structure that lies outside the plasma membrane and surrounds the entire cell."

"That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid."

“Those processes specifically pertinent to the functioning of integrated living units: cells, tissues, organs, and organisms."...

"A phenomenon marked by changes that lead to a particular result, mediated by one or more gene products."

"Processes that are carried out at the cellular level, but are not necessarily restricted to a single cell. For example, cell communication occurs among more than one cell, but occurs at the cellular level."

"The processes pertinent to the integrated function of a cell."

related_synonym: "Enzyme activity"
"Catalysis of a biochemical reaction at physiological temperatures. In biologically catalyzed reactions, the reactants are known as substrates, and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites for substrates, and are usually composed wholly or largely of protein, but RNA that has catalytic activity (ribozyme) is often also regarded as enzymatic."
Note: see the Wikipedia enzymes category.

exact_synonym: "estrogen synthetase"
"Catalysis of the reaction: R-H + reduced flavoprotein + O2 = R-OH + oxidized flavoprotein + H2O."

• See the Wikipedia EC 1.14.14 category.

Catalysis of movement along a polymeric molecule such as a microfilament or microtubule, coupled to the hydrolysis of a nucleoside triphosphate. Also includes prokaryotic motors.
Note: the myosin, kinesin and dynein motor proteins are also in the cytoskeleton category.
See the Wikipedia Motor protein article and the motor proteins category of Wikipedia.

"Catalysis of the unwinding of a DNA or RNA duplex."

• dnaB
• recQ

"Catalysis of the integration of DNA possibly by forming a transient DNA-protein link."

"Inhibition of the reactions brought about by dioxygen (O2) or peroxides. Usually the antioxidant is effective because it can itself be more easily oxidized than the substance protected. The term is often applied to components that can trap free radicals, thereby breaking the chain reaction that normally leads to extensive biological damage."

"Processes that cause many of the chemical changes in living organisms, including anabolism and catabolism. Metabolic processes typically transform small molecules, but also include macromolecular processes such as DNA repair and replication, and protein synthesis and degradation." Note that metabolic processes do not include single functions or processes such as protein-protein interactions, protein-nucleic acids, nor receptor-ligand interactions.

The chemical reactions involving macromolecules (large molecules including proteins, nucleic acids and carbohydrates). See also: #catabolism.

• Protease
  • Category:EC 3.4
• Protease inhibitors
  • Serine protease inhibitors category

"The chemical reactions involving amino acids, organic acids containing one or more amino substituents, and compounds derived from amino acids."

"The chemical reactions involving nucleobases, nucleosides, nucleotides and nucleic acids."

"The energy-requiring part of metabolism in which simpler substances are transformed into more complex ones, as in growth and other biosynthetic processes."

exact_synonym: "breakdown"
exact_synonym: "degradation"
"Any metabolic process involving the breakdown of complex substances into smaller products, including the breakdown of carbon compounds with the liberation of energy for use by the cell or organism."
Note: use #macromolecule metabolism (above) for proteins, nucleic acids and carbohydrates.

"Catalysis of the transfer of a phosphate group, usually from ATP, to a substrate molecule."

"Catalysis of an oxidation-reduction (redox) reaction; a reversible chemical reaction in which the oxidation state of an atom or atoms within a molecule is altered. One substrate acts as a hydrogen or electron donor and becomes oxidized, while the other acts as hydrogen or electron acceptor and becomes reduced."

"Catalysis of the transfer of a group, e.g. a methyl group, glycosyl group, acyl group, phosphorus-containing, or other groups, from one compound (generally regarded as the donor) to another compound (generally regarded as the acceptor). Transferase is the systematic name for any enzyme of EC class 2."

"Catalysis of the hydrolysis of various bonds, e.g. C-O, C-N, C-C, phosphoric anhydride bonds, etc. Hydrolase is the systematic name for any enzyme of EC class 3."

"Catalysis of the cleavage of C-C, C-O, C-N and other bonds by other means than by hydrolysis or oxidation, or conversely adding a group to a double bond. They differ from other enzymes in that two substrates are involved in one reaction direction, but only one in the other direction. When acting on the single substrate, a molecule is eliminated and this generates either a new double bond or a new ring." (EC:4)

"Catalysis of the geometric or structural changes within one molecule. Isomerase is the systematic name for any enzyme of EC class 5."

"Catalysis of the ligation of two substances with concomitant breaking of a diphosphate linkage, usually in a nucleoside triphosphate. Ligase is the systematic name for any enzyme of EC class 6."

"Modulates the activity of an enzyme."
exact_synonym: "enzyme modulator"

namespace: molecular_function def: "Mediates the transfer of a signal from the outside to the inside of a cell by means other than the introduction of the signal molecule itself into the cell."

"The action of a molecule that contributes to the structural integrity of a complex or assembly within or outside a cell."

The cytoskeleton is composed of protein filaments in the cytoplasm.

• The Wikipedia Cytoskeleton category.

"A layer consisting mainly of proteins (especially collagen) and glycosaminoglycans (mostly as proteoglycans) that forms a sheet underlying cells such as endothelial and epithelial cells. The proteins are secreted by cells in the vicinity. As in, but not restricted to, the multicellular animals.

"The selective, often stoichiometric interaction of a molecule with one or more specific sites on another molecule." For ligands that bind to signal transducing receptors, consider the molecular function term 'receptor binding' (receptor activity, below)

"Combining with an extracellular or intracellular messenger to initiate a change in cell activity."

The Wikipedia Receptors category.

"Interacting selectively with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules)."

"Interacting selectively and non-covalently with a lipid." (GO:0008289)

• Lipid transfer proteins

"Any process involved in the controlled movement of a cell."
exact_synonym: "cell locomotion"
exact_synonym: "cell movement" Note: also see #motor activity (above) for other proteins involved in cell motility.

"The joining of two lipid bilayers to form a single membrane."

"Any process that mediates interactions between a cell and its surroundings. Encompasses interactions such as signaling or attachment between one cell and another cell, between a cell and an extracellular matrix, or between a cell and any other aspect of its environment."

"Any process that modulates the frequency, rate or extent of a biological process. Biological processes are regulated by many means; examples include the control of gene expression, protein modification or interaction with a protein or substrate molecule."

"The biological process specifically aimed at the progression of an organism over time from an initial condi (e.g. a multicellular animal, an aged adult or a mature single celled organism)." ('developmental process').

"The process whereby relatively unspecialized cells, e.g. embryonic or regenerative cells, acquire specialized structural and/or functional features that characterize the cells, tissues, or organs of the mature organism or some other relatively stable phase of the organism's life history."

"A change in state or activity of a cell or organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of the perception of a stimulus."

"The specific actions or reactions of an organism in response to external or internal stimuli. Patterned activity of a whole organism in a manner dependent upon some combination of that organism's internal state and external conditions."

"The specific aalting of processes within a cell so that its vital functions markedly cease, rather than simply deteriorating gradually over time, which culminates in cell death."

"The directed movement of substances (such as macromolecules, small molecules, ions) into, out of, within or between cells."

"Enables the directed movement of proteins into, out of, within or between cells."

• importin, nuclear transport factor 2 (NTF2), Ran, exportin

"Enables the directed movement of charged atoms or small charged molecules into, out of, within or between cells."

"Allows facilitated diffusion (by an energy-independent process) by passage through a transmembrane aqueous pore or channel without a carrier-mediated mechanism. They do not exhibit stereospecificity but may be specific for a particular molecular species or class of molecules."

exact synonym: "carrier type transporter"
"Catalysis of the transfer of a specific substance or related group of substances from one side of the membrane to the other."

"Catalysis of the stereospecific transfer of a substrate across a biological membrane."

"The regulated release of a substance by a cell or group of cells."

"Enables the directed movement of electrons into, out of, within or between cells."

"The transport of electrons from an electron donor to an electron acceptor." (electron transfer)

"The specific processes that generate the ability of an organism to cause disease in another."
Note that this term should not be used to annotate gene products that are involved in the host response to pathogenesis. It should only be used to annotate those gene products involved in the generation of pathogenesis by the pathogen itself (virulence).

"Modulates the activity of a molecular chaperone."

"Interacting selectively with any nucleic acid."

"Plays a role in regulating transcription; may bind a promoter or enhancer DNA sequence or interact with a DNA-binding transcription factor."
Category:Transcription factors
Category:Transcription coregulators; Transcription coregulators like PELP-1; Coactivator (genetics)

"The assembly and arrangement of structures in the space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane, and also covers the host cell environment outside an intracellular parasite."
exact_synonym: "extracellular structure organization and biogenesis"

"Any substance involved in the initiation, activation, perpetuation, repression or termination of polypeptide synthesis at the ribosome."