P78810 · VTC4_SCHPO
- ProteinVacuolar transporter chaperone complex subunit 4
- Genevtc4
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids721 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalytic subunit of the vacuolar transporter chaperone (VTC) complex. The VTC complex acts as a vacuolar polyphosphate polymerase that catalyzes the synthesis of inorganic polyphosphate (polyP) via transfer of phosphate from ATP to a growing polyP chain, releasing ADP. VTC exposes its catalytic domain vtc4 to the cytosol, where the growing polyP chain winds through a tunnel-shaped pocket, integrating cytoplasmic polymer synthesis with polyP membrane translocation. The VTC complex carries 9 vacuolar transmembrane domains, which are likely to constitute the translocation channel into the organelle lumen. PolyP synthesis is tightly coupled to its transport into the vacuole lumen, in order to avoid otherwise toxic intermediates in the cytosol, and it depends on the proton gradient across the membrane, formed by V-ATPase. The VTC complex also plays a role in vacuolar membrane fusion.
Catalytic activity
- [phosphate](n) + ATP = [phosphate](n+1) + ADPThis reaction proceeds in the forward direction.
Cofactor
Activity regulation
Activity of the enzyme is Mn2+-dependent and enhanced in the presence of pyrophosphate (PPi).
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 198 | ATP (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 262 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 264 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 279 | ATP (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 292 | ATP (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 357 | ATP (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 359 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 421 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Active site | 453 | |||||
Sequence: K |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | fungal-type vacuole membrane | |
Cellular Component | vacuolar transporter chaperone complex | |
Molecular Function | ATP binding | |
Molecular Function | metal ion binding | |
Molecular Function | transferase activity | |
Biological Process | energy reserve metabolic process | |
Biological Process | microautophagy | |
Biological Process | polyphosphate biosynthetic process | |
Biological Process | polyphosphate metabolic process | |
Biological Process | vacuolar transport | |
Biological Process | vacuole fusion, non-autophagic |
Keywords
- Molecular function
- Ligand
Names & Taxonomy
Protein names
- Recommended nameVacuolar transporter chaperone complex subunit 4
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Taphrinomycotina > Schizosaccharomycetes > Schizosaccharomycetales > Schizosaccharomycetaceae > Schizosaccharomyces
Accessions
- Primary accessionP78810
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Vacuole membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-631 | Cytoplasmic | ||||
Sequence: MKFGQLLKETLMYEYKYSYVNYDKLKKEIKRRNDQGGWSEEDESDFVELLEKELDKVYSFQKNKSAEVMERIRFCEEQTDEVVRRLDSDNPPNENDFAILETELTDIMATVHDLAKFSELNYTAFYKIIKKHDKHTGWILKPVFAARLNAKPFFKEQYDLLVVKLSKLYDFVRTRGSPIKGDSAAGGTQQNFVRQTTKYWVHPNNVTELKIYILKHLPVLVFNPNKEFAREDAAITSIYYDNDDLDFYLGRLEKREGAEAIRLRWYGNMDNNNIFVERKTHREDWTGEKSVKARFPLKEKYVNAFLRGDYTVEEAFAKMRKDGKKSLKEIESLERLAKEVQYTVLSRGMKPYVRSFYERTAFQLPGDARVRISLDTNLSLIREDGPSRAGNNWRRMDIGIDYPFDQLPDEDIVRFPYAILEVKLQTQFGQDPPEWVNNLVNSHLVEAVPKFSKFIHGVSTLFYDRVTLLPYWFPQMDIDIRKPATHTFIQGRSQSGTHSSSVSANVLTDSENTPIHADGDNYVDEESRIGSSSTRNDNSTFQTSDSFQELDERTNLLDISKRKGRDSFVAALNSRLKDIKDSFFLETVPKFEEPTEPTVIYEQKYVSPPGKRIYVPVRVEPKTYFALERTY | ||||||
Transmembrane | 632-652 | Helical | ||||
Sequence: LDYLRYSILMGSIGITLFSFA | ||||||
Topological domain | 653-657 | Vacuolar | ||||
Sequence: KTRSG | ||||||
Transmembrane | 658-678 | Helical | ||||
Sequence: ILGAASFTLVALFAIFYSTFL | ||||||
Topological domain | 679-697 | Cytoplasmic | ||||
Sequence: YLWRAVNIAKHNAVRYDDR | ||||||
Transmembrane | 698-718 | Helical | ||||
Sequence: FGPTAICVITFAAISANVILN | ||||||
Topological domain | 719-721 | Vacuolar | ||||
Sequence: FNA |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000363396 | 1-721 | Vacuolar transporter chaperone complex subunit 4 | |||
Sequence: MKFGQLLKETLMYEYKYSYVNYDKLKKEIKRRNDQGGWSEEDESDFVELLEKELDKVYSFQKNKSAEVMERIRFCEEQTDEVVRRLDSDNPPNENDFAILETELTDIMATVHDLAKFSELNYTAFYKIIKKHDKHTGWILKPVFAARLNAKPFFKEQYDLLVVKLSKLYDFVRTRGSPIKGDSAAGGTQQNFVRQTTKYWVHPNNVTELKIYILKHLPVLVFNPNKEFAREDAAITSIYYDNDDLDFYLGRLEKREGAEAIRLRWYGNMDNNNIFVERKTHREDWTGEKSVKARFPLKEKYVNAFLRGDYTVEEAFAKMRKDGKKSLKEIESLERLAKEVQYTVLSRGMKPYVRSFYERTAFQLPGDARVRISLDTNLSLIREDGPSRAGNNWRRMDIGIDYPFDQLPDEDIVRFPYAILEVKLQTQFGQDPPEWVNNLVNSHLVEAVPKFSKFIHGVSTLFYDRVTLLPYWFPQMDIDIRKPATHTFIQGRSQSGTHSSSVSANVLTDSENTPIHADGDNYVDEESRIGSSSTRNDNSTFQTSDSFQELDERTNLLDISKRKGRDSFVAALNSRLKDIKDSFFLETVPKFEEPTEPTVIYEQKYVSPPGKRIYVPVRVEPKTYFALERTYLDYLRYSILMGSIGITLFSFAKTRSGILGAASFTLVALFAIFYSTFLYLWRAVNIAKHNAVRYDDRFGPTAICVITFAAISANVILNFNA | ||||||
Modified residue | 495 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 497 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 501 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 534 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 546 | Phosphoserine | ||||
Sequence: S |
Keywords
- PTM
Proteomic databases
PTM databases
Interaction
Subunit
The VTC core complex is an integral membrane heterooligomer composed of at least the catalytic subunit vtc4 and the accessory subunits vtc1 and vtc2. vtc1 is a small membrane protein without hydrophilic domain. Vtc2 and vtc4 are related and have 2 hydrophilic domains that face the cytosol, an N-terminal SPX domain and the central core domain. The central core in vtc4 is the catalytic domain.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain, compositional bias, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 1-146 | SPX | ||||
Sequence: MKFGQLLKETLMYEYKYSYVNYDKLKKEIKRRNDQGGWSEEDESDFVELLEKELDKVYSFQKNKSAEVMERIRFCEEQTDEVVRRLDSDNPPNENDFAILETELTDIMATVHDLAKFSELNYTAFYKIIKKHDKHTGWILKPVFAA | ||||||
Compositional bias | 490-515 | Polar residues | ||||
Sequence: QGRSQSGTHSSSVSANVLTDSENTPI | ||||||
Region | 490-547 | Disordered | ||||
Sequence: QGRSQSGTHSSSVSANVLTDSENTPIHADGDNYVDEESRIGSSSTRNDNSTFQTSDSF | ||||||
Compositional bias | 526-547 | Polar residues | ||||
Sequence: ESRIGSSSTRNDNSTFQTSDSF |
Domain
The SPX domain has very high affinity for inositol polyphosphates. SPX domains may integrate inositol pyrophosphates (PP-InsP)-dependent signaling to adapt cytosolic phosphate concentrations to different metabolic situations.
Sequence similarities
Belongs to the VTC4 family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length721
- Mass (Da)83,635
- Last updated2000-06-01 v2
- ChecksumDF4471E8FC0A6BCF
Features
Showing features for compositional bias, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 490-515 | Polar residues | ||||
Sequence: QGRSQSGTHSSSVSANVLTDSENTPI | ||||||
Compositional bias | 526-547 | Polar residues | ||||
Sequence: ESRIGSSSTRNDNSTFQTSDSF | ||||||
Sequence conflict | 580 | in Ref. 2; BAA13821 | ||||
Sequence: K → R | ||||||
Sequence conflict | 714 | in Ref. 2; BAA13821 | ||||
Sequence: N → Y |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CU329672 EMBL· GenBank· DDBJ | CAA22867.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
D89159 EMBL· GenBank· DDBJ | BAA13821.1 EMBL· GenBank· DDBJ | mRNA |