The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was: waiting to be named.

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 1: Cystatin-A

Please note: GO annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

There are 11 GO terms relating to "molecular function"

The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.
GO Term Annotations Evidence
Cysteine-type endopeptidase inhibitor activity GO:0004869
Stops, prevents or reduces the activity of a cysteine-type endopeptidase, any enzyme that hydrolyzes peptide bonds in polypeptides by a mechanism in which the sulfhydryl group of a cysteine residue at the active center acts as a nucleophile.
12 B2Z449 (/IDA) J7FQE8 (/IDA) P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA)
(2 more)
Protease binding GO:0002020
Interacting selectively and non-covalently with any protease or peptidase.
8 P01040 (/IPI) P01040 (/IPI) P04080 (/IPI) P04080 (/IPI) P04080 (/IPI) P04080 (/IPI) P04080 (/IPI) P04080 (/IPI)
RNA binding GO:0003723
Interacting selectively and non-covalently with an RNA molecule or a portion thereof.
6 P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA)
Endopeptidase inhibitor activity GO:0004866
Stops, prevents or reduces the activity of an endopeptidase, any enzyme that hydrolyzes nonterminal peptide bonds in polypeptides.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Protease binding GO:0002020
Interacting selectively and non-covalently with any protease or peptidase.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Cysteine-type endopeptidase inhibitor activity GO:0004869
Stops, prevents or reduces the activity of a cysteine-type endopeptidase, any enzyme that hydrolyzes peptide bonds in polypeptides by a mechanism in which the sulfhydryl group of a cysteine residue at the active center acts as a nucleophile.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Endopeptidase inhibitor activity GO:0004866
Stops, prevents or reduces the activity of an endopeptidase, any enzyme that hydrolyzes nonterminal peptide bonds in polypeptides.
2 P35174 (/IDA) P35175 (/IDA)
Endopeptidase inhibitor activity GO:0004866
Stops, prevents or reduces the activity of an endopeptidase, any enzyme that hydrolyzes nonterminal peptide bonds in polypeptides.
1 Q62426 (/ISO)
Cysteine-type endopeptidase inhibitor activity GO:0004869
Stops, prevents or reduces the activity of a cysteine-type endopeptidase, any enzyme that hydrolyzes peptide bonds in polypeptides by a mechanism in which the sulfhydryl group of a cysteine residue at the active center acts as a nucleophile.
1 Q5R1U3 (/ISS)
Protein binding GO:0005515
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
1 P01041 (/IPI)
Peptidase inhibitor activity GO:0030414
Stops, prevents or reduces the activity of a peptidase, any enzyme that catalyzes the hydrolysis peptide bonds.
1 G8IIS4 (/IDA)

There are 16 GO terms relating to "biological process"

The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.
GO Term Annotations Evidence
Negative regulation of peptidase activity GO:0010466
Any process that stops or reduces the rate of peptidase activity, the hydrolysis of peptide bonds within proteins.
8 P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA)
Negative regulation of proteolysis GO:0045861
Any process that stops, prevents, or reduces the frequency, rate or extent of the hydrolysis of a peptide bond or bonds within a protein.
8 P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA)
Neutrophil degranulation GO:0043312
The regulated exocytosis of secretory granules containing preformed mediators such as proteases, lipases, and inflammatory mediators by a neutrophil.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Negative regulation of endopeptidase activity GO:0010951
Any process that decreases the frequency, rate or extent of endopeptidase activity, the endohydrolysis of peptide bonds within proteins.
3 J7FQE8 (/IDA) P35174 (/IDA) P35175 (/IDA)
Proteolysis GO:0006508
The hydrolysis of proteins into smaller polypeptides and/or amino acids by cleavage of their peptide bonds.
2 Q65YR7 (/IDA) Q65YR8 (/IDA)
Peptide cross-linking GO:0018149
The formation of a covalent cross-link between or within protein chains.
2 P01040 (/IDA) P01040 (/IDA)
Keratinocyte differentiation GO:0030216
The process in which a relatively unspecialized cell acquires specialized features of a keratinocyte.
2 P01040 (/IDA) P01040 (/IDA)
Cornification GO:0070268
A type of programmed cell death that occurs in the epidermis, morphologically and biochemically distinct from apoptosis. It leads to the formation of corneocytes, i.e. dead keratinocytes containing an amalgam of specific proteins (e.g., keratin, loricrin, SPR and involucrin) and lipids (e.g., fatty acids and ceramides), which are necessary for the function of the cornified skin layer (mechanical resistance, elasticity, water repellence and structural stability).
2 P01040 (/TAS) P01040 (/TAS)
Cellular response to bacterial lipoprotein GO:0071220
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a bacterial lipoprotein stimulus.
2 B2Z449 (/IPI) J7FQE8 (/IPI)
Cell-cell adhesion GO:0098609
The attachment of one cell to another cell via adhesion molecules.
2 P01040 (/IMP) P01040 (/IMP)
Proteolysis GO:0006508
The hydrolysis of proteins into smaller polypeptides and/or amino acids by cleavage of their peptide bonds.
1 Q5R1U3 (/ISS)
Hyperosmotic response GO:0006972
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of detection of, or exposure to, a hyperosmotic environment, i.e. an environment with a higher concentration of solutes than the organism or cell.
1 Q5R1U3 (/IEP)
Adult locomotory behavior GO:0008344
Locomotory behavior in a fully developed and mature organism.
1 Q62426 (/IMP)
Response to bacterium GO:0009617
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus from a bacterium.
1 Q65YR8 (/HEP)
Negative regulation of peptidase activity GO:0010466
Any process that stops or reduces the rate of peptidase activity, the hydrolysis of peptide bonds within proteins.
1 Q62426 (/ISO)
Negative regulation of proteolysis GO:0045861
Any process that stops, prevents, or reduces the frequency, rate or extent of the hydrolysis of a peptide bond or bonds within a protein.
1 Q62426 (/ISO)

There are 25 GO terms relating to "cellular component"

The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.
GO Term Annotations Evidence
Cytosol GO:0005829
The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.
16 P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) Q65YR7 (/IDA) Q65YR8 (/IDA)
(6 more)
Nucleolus GO:0005730
A small, dense body one or more of which are present in the nucleus of eukaryotic cells. It is rich in RNA and protein, is not bounded by a limiting membrane, and is not seen during mitosis. Its prime function is the transcription of the nucleolar DNA into 45S ribosomal-precursor RNA, the processing of this RNA into 5.8S, 18S, and 28S components of ribosomal RNA, and the association of these components with 5S RNA and proteins synthesized outside the nucleolus. This association results in the formation of ribonucleoprotein precursors; these pass into the cytoplasm and mature into the 40S and 60S subunits of the ribosome.
12 P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) Q76LA1 (/IDA) Q76LA1 (/IDA) Q76LA1 (/IDA) Q76LA1 (/IDA)
(2 more)
Cytoplasm GO:0005737
All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
9 P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P35175 (/IDA)
Extracellular space GO:0005615
That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.
8 P01040 (/IDA) P01040 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA) P04080 (/IDA)
Collagen-containing extracellular matrix GO:0062023
An extracellular matrix consisting mainly of proteins (especially collagen) and glycosaminoglycans (mostly as proteoglycans) that provides not only essential physical scaffolding for the cellular constituents but can also initiate crucial biochemical and biomechanical cues required for tissue morphogenesis, differentiation and homeostasis. The components are secreted by cells in the vicinity and form a sheet underlying or overlying cells such as endothelial and epithelial cells.
7 P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) Q62426 (/HDA)
Extracellular region GO:0005576
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.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Extracellular space GO:0005615
That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.
6 P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA)
Secretory granule lumen GO:0034774
The volume enclosed by the membrane of a secretory granule.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Extracellular exosome GO:0070062
A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm.
6 P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA) P04080 (/HDA)
Tertiary granule lumen GO:1904724
Any membrane-enclosed lumen that is part of a tertiary granule.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Ficolin-1-rich granule lumen GO:1904813
Any membrane-enclosed lumen that is part of a ficolin-1-rich granule.
6 P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS) P04080 (/TAS)
Extracellular space GO:0005615
That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Nucleus GO:0005634
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.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Cytoplasm GO:0005737
All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Cytosol GO:0005829
The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.
5 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q62426 (/ISO) Q9D8D6 (/ISO)
Cornified envelope GO:0001533
A type of plasma membrane that has been modified through addition of distinct intracellular and extracellular components, including ceramide, found in cornifying epithelial cells (corneocytes).
4 B2RV77 (/ISO) P56567 (/ISO) P56567 (/ISO) Q9D8D6 (/ISO)
Cornified envelope GO:0001533
A type of plasma membrane that has been modified through addition of distinct intracellular and extracellular components, including ceramide, found in cornifying epithelial cells (corneocytes).
2 P01040 (/IDA) P01040 (/IDA)
Cornified envelope GO:0001533
A type of plasma membrane that has been modified through addition of distinct intracellular and extracellular components, including ceramide, found in cornifying epithelial cells (corneocytes).
2 P01040 (/TAS) P01040 (/TAS)
Nucleus GO:0005634
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.
2 P01040 (/IDA) P01040 (/IDA)
Cytoplasm GO:0005737
All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.
2 B2Z449 (/ISS) J7FQE8 (/ISS)
Cytosol GO:0005829
The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.
2 P01040 (/TAS) P01040 (/TAS)
Nucleolus GO:0005730
A small, dense body one or more of which are present in the nucleus of eukaryotic cells. It is rich in RNA and protein, is not bounded by a limiting membrane, and is not seen during mitosis. Its prime function is the transcription of the nucleolar DNA into 45S ribosomal-precursor RNA, the processing of this RNA into 5.8S, 18S, and 28S components of ribosomal RNA, and the association of these components with 5S RNA and proteins synthesized outside the nucleolus. This association results in the formation of ribonucleoprotein precursors; these pass into the cytoplasm and mature into the 40S and 60S subunits of the ribosome.
1 Q62426 (/ISO)
Lysosome GO:0005764
A small lytic vacuole that has cell cycle-independent morphology and is found in most animal cells and that contains a variety of hydrolases, most of which have their maximal activities in the pH range 5-6. The contained enzymes display latency if properly isolated. About 40 different lysosomal hydrolases are known and lysosomes have a great variety of morphologies and functions.
1 G8IIS4 (/IDA)
Vesicle GO:0031982
Any small, fluid-filled, spherical organelle enclosed by membrane.
1 Q65YR8 (/IDA)
Phagocytic vesicle GO:0045335
A membrane-bounded intracellular vesicle that arises from the ingestion of particulate material by phagocytosis.
1 Q65YR8 (/HDA)
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