O07032 · MLEP_LACLA

Function

function

Secondary transporter involved in malolactic fermentation (PubMed:1917837, PubMed:9218448).
Catalyzes the uptake of divalent malate into the cell coupled to the exit of monovalent lactate, a product of malate degradation (precursor/product exchange) (PubMed:1917837, PubMed:9218448, PubMed:10441129).
The malate/lactate exchange is electrogenic and results in the generation of a membrane potential (PubMed:1917837, PubMed:9218448).
Is highly selective for the S-enantiomer of malate (PubMed:10441129).
In the absence of lactate, MleP can also catalyze the proton-dependent transport of malate (PubMed:1917837).
In vitro, transports a range of substrates that contain the 2-hydroxycarboxylate motif, HO-CR2-COO-, with a preference for malate, lactate and glycolate (PubMed:10441129, PubMed:9218448).
Modification of the OH or the COO- groups of the 2-hydroxycarboxylate motif drastically reduces the affinity of the transporter for the substrates, indicating their relevance in substrate recognition (PubMed:10441129).
Significant activity is also observed with some 2-oxocarboxylates (PubMed:9218448).
Transports only poorly citromalate (PubMed:10441129, PubMed:9218448).
Citrate binds to MleP but is not translocated (PubMed:10441129, PubMed:9218448).

Catalytic activity

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
4.6 mM(S)-lactate
14 mM(R)-lactate
0.46 mM(S)-malate
0.47 mM(S)-malate

GO annotations

AspectTerm
Cellular Componentplasma membrane
Molecular Functionantiporter activity
Molecular Functionorganic anion transmembrane transporter activity
Molecular Functionsymporter activity

Keywords

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Malate transporter MleP
  • Alternative names
    • Malate/lactate antiporter

Gene names

    • Name
      mleP
    • ORF names
      L123159

Organism names

Accessions

  • Primary accession
    O07032

Proteomes

Subcellular Location

Cell membrane
; Multi-pass membrane protein

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane11-31Helical
Transmembrane35-55Helical
Transmembrane65-85Helical
Transmembrane96-116Helical
Transmembrane134-154Helical
Transmembrane196-216Helical
Transmembrane246-266Helical
Transmembrane269-289Helical
Transmembrane310-330Helical
Transmembrane339-359Helical
Transmembrane401-421Helical

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004605551-425Malate transporter MleP

Proteomic databases

Family & Domains

Domain

The 46 C-terminal residues contain structural elements that interact with the R groups of the substrates (PubMed:11041872).
Interchanging the 46 C-terminal amino acid residues of CitP and MleP alters neither the specificity nor the affinity for the di- and tricarboxylates malate and citrate (PubMed:11041872).
In contrast, changes in substrate specificity are observed with monocarboxylates (PubMed:11041872).

Sequence similarities

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    425
  • Mass (Da)
    45,309
  • Last updated
    1997-07-01 v1
  • Checksum
    4A435EA335352AF0
MKKLKETKISGISLPLYAFFVAVIIVVTLLGKLPLDMVGLTLLLVTLGHLLYFIGEKFPIMNSYLGGGSVFTLIGATLLSFFHIVPSNVIGAVSNFMGGKFGFLDFYIAALICGSILGMNRNLLVKASKKFIPIALITMVIGFFSVGLVGMLIGNGFADSVMYVSMPMMSGGMGAGITPLSQIYAAGLAHGNQAAIFSQLAPAVTFGNILAIIGALSIAKVFNKSKYNGHGTLVAATKEELAKPKIKLDAQQIGTGMLFAFALLMAGDILNKFFPNIHQYAFMIIIVFILKATNTVPKDLEESVVMFNQVIMTNLTHAVLAGIGLALIDLNTLASAFTWQFVVLCLTSVVVMGLASWFLARLFGLYPVETAIGAGMINNSMGGTGNIAVLSASDRMEMIAFAQMANRLCGAIVLIFGGILIRFFY

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
X75982
EMBL· GenBank· DDBJ
CAA53590.1
EMBL· GenBank· DDBJ
Genomic DNA
AE005176
EMBL· GenBank· DDBJ
AAK04999.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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