P68187 · MALK_ECOLI

  • Protein
    Maltose/maltodextrin import ATP-binding protein MalK
  • Gene
    malK
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

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

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site36-43ATP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular ComponentATP-binding cassette (ABC) transporter complex
Cellular ComponentATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing
Cellular Componentenzyme IIA-maltose transporter complex
Cellular Componentmaltose transport complex
Cellular Componentmembrane
Molecular FunctionABC-type maltose transporter activity
Molecular FunctionATP binding
Molecular FunctionATP hydrolysis activity
Molecular FunctionDNA-binding transcription factor binding
Biological Processmaltodextrin transmembrane transport
Biological Processmaltose transport
Biological Processnegative regulation of maltose transport
Biological Processnegative regulation of transmembrane transport

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Maltose/maltodextrin import ATP-binding protein MalK
  • EC number

Gene names

    • Name
      malK
    • Ordered locus names
      b4035, JW3995

Organism names

  • Taxonomic identifier
  • Strains
    • K12
    • K12 / MG1655 / ATCC 47076
    • K12 / W3110 / ATCC 27325 / DSM 5911
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P68187
  • Secondary accessions
    • P02914
    • Q2M6R9
    • Q47348

Proteomes

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis85Suppressor of EAA loop mutations in MalFG.
Mutagenesis106Suppressor of EAA loop mutations in MalFG.
Mutagenesis114Suppressor of EAA loop mutations in MalFG.
Mutagenesis117Suppressor of EAA loop mutations in MalFG.
Mutagenesis119Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis124Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis137Loss of maltose transport. Has greater ability to decrease mal gene expression than wild-type MalK.
Mutagenesis158Loss of maltose transport but retains ability to repress mal genes.
Mutagenesis228Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis241Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis267Normal maltose transport but constitutive mal gene expression.
Mutagenesis278Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis282Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis284Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis302Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis308Maltose transport is affected but retains ability to interact with MalT.
Mutagenesis322Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity.
Mutagenesis340Maltose transport is affected but retains ability to interact with MalT.
Mutagenesis346Normal maltose transport but constitutive mal gene expression.
Mutagenesis355Maltose transport is affected but retains ability to interact with MalT.

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000924751-371Maltose/maltodextrin import ATP-binding protein MalK

Proteomic databases

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

View interactors in UniProtKB
View CPX-1932 in Complex Portal

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain4-234ABC transporter

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    371
  • Mass (Da)
    40,990
  • Last updated
    2004-10-25 v1
  • MD5 Checksum
    599AA7BB9ACB7C8383CD6E9A94258FBF
MASVQLQNVTKAWGEVVVSKDINLDIHEGEFVVFVGPSGCGKSTLLRMIAGLETITSGDLFIGEKRMNDTPPAERGVGMVFQSYALYPHLSVAENMSFGLKLAGAKKEVINQRVNQVAEVLQLAHLLDRKPKALSGGQRQRVAIGRTLVAEPSVFLLDEPLSNLDAALRVQMRIEISRLHKRLGRTMIYVTHDQVEAMTLADKIVVLDAGRVAQVGKPLELYHYPADRFVAGFIGSPKMNFLPVKVTATAIDQVQVELPMPNRQQVWLPVESRDVQVGANMSLGIRPEHLLPSDIADVILEGEVQVVEQLGNETQIHIQIPSIRQNLVYRQNDVVLVEEGATFAIGLPPERCHLFREDGTACRRLHKEPGV

Sequence caution

The sequence CAA23582.1 differs from that shown. Reason: Erroneous initiation Extended N-terminus.

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict220-241in Ref. 1; AAB59057

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
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

Genome annotation databases

Similar Proteins

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