P68187 · MALK_ECOLI
- ProteinMaltose/maltodextrin import ATP-binding protein MalK
- GenemalK
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids371 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Part of the ABC transporter complex MalEFGK involved in maltose/maltodextrin import. Responsible for energy coupling to the transport system.
Miscellaneous
Target for inducer exclusion, mediated by the unphosphorylated enzyme III of the phosphotransferase system for glucose and resulting in the inhibition of maltose transport.
Acts as a repressor of mal genes. In absence of maltose, the C-terminus of MalK interacts with MalT, then MalT becomes inactive and the mal genes are not activated. In presence of maltose, MalK is tightly associated with the MalFG complex and has no affinity for MalT.
Catalytic activity
- D-maltose(out) + ATP + H2O = D-maltose(in) + ADP + phosphate + H+D-maltose (out)CHEBI:17306
+ CHEBI:30616 + CHEBI:15377 = D-maltose (in)CHEBI:17306+ CHEBI:456216 + CHEBI:43474 + CHEBI:15378
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 36-43 | ATP (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | ATP-binding cassette (ABC) transporter complex | |
Cellular Component | ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing | |
Cellular Component | enzyme IIA-maltose transporter complex | |
Cellular Component | maltose transport complex | |
Cellular Component | membrane | |
Molecular Function | ABC-type maltose transporter activity | |
Molecular Function | ATP binding | |
Molecular Function | ATP hydrolysis activity | |
Molecular Function | DNA-binding transcription factor binding | |
Biological Process | maltodextrin transmembrane transport | |
Biological Process | maltose transport | |
Biological Process | negative regulation of maltose transport | |
Biological Process | negative regulation of transmembrane transport |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameMaltose/maltodextrin import ATP-binding protein MalK
- EC number
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia
Accessions
- Primary accessionP68187
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Cell inner membrane ; Peripheral membrane protein
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 85 | Suppressor of EAA loop mutations in MalFG. | |||
Mutagenesis | 106 | Suppressor of EAA loop mutations in MalFG. | |||
Mutagenesis | 114 | Suppressor of EAA loop mutations in MalFG. | |||
Mutagenesis | 117 | Suppressor of EAA loop mutations in MalFG. | |||
Mutagenesis | 119 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 124 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 137 | Loss of maltose transport. Has greater ability to decrease mal gene expression than wild-type MalK. | |||
Mutagenesis | 158 | Loss of maltose transport but retains ability to repress mal genes. | |||
Mutagenesis | 228 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 241 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 267 | Normal maltose transport but constitutive mal gene expression. | |||
Mutagenesis | 278 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 282 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 284 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 302 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 308 | Maltose transport is affected but retains ability to interact with MalT. | |||
Mutagenesis | 322 | Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. | |||
Mutagenesis | 340 | Maltose transport is affected but retains ability to interact with MalT. | |||
Mutagenesis | 346 | Normal maltose transport but constitutive mal gene expression. | |||
Mutagenesis | 355 | Maltose transport is affected but retains ability to interact with MalT. | |||
Interaction
Subunit
The complex is composed of two ATP-binding proteins (MalK), two transmembrane proteins (MalG and MalF) and a solute-binding protein (MalE). Protein stability and stable complex formation require YidC.
Complex viewer
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Domain | 4-234 | ABC transporter | |||
Sequence similarities
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length371
- Mass (Da)40,990
- Last updated2004-10-25 v1
- MD5 Checksum599AA7BB9ACB7C8383CD6E9A94258FBF
Sequence caution
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Sequence conflict | 220-241 | in Ref. 1; AAB59057 | |||
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
J01648 EMBL· GenBank· DDBJ | AAB59057.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U00006 EMBL· GenBank· DDBJ | AAC43129.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U00096 EMBL· GenBank· DDBJ | AAC77005.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AP009048 EMBL· GenBank· DDBJ | BAE78037.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
V00303 EMBL· GenBank· DDBJ | CAA23582.1 EMBL· GenBank· DDBJ | Genomic DNA | Different initiation |