O07032 · MLEP_LACLA
- ProteinMalate transporter MleP
- GenemleP
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids425 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score3/5
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).
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
- (S)-lactate(in) + (S)-malate(out) = (S)-lactate(out) + (S)-malate(in)This reaction proceeds in the forward direction.(S)-lactate (in)CHEBI:16651
+ (S)-malate (out)CHEBI:15589= (S)-lactate (out)CHEBI:16651+ (S)-malate (in)CHEBI:15589 - (R)-lactate(in) + (S)-malate(out) = (R)-lactate(out) + (S)-malate(in)This reaction proceeds in the forward direction.
- (S)-malate(out) + glycolate(in) = (S)-malate(in) + glycolate(out)
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
Aspect | Term | |
---|---|---|
Cellular Component | plasma membrane | |
Molecular Function | antiporter activity | |
Molecular Function | organic anion transmembrane transporter activity | |
Molecular Function | symporter activity |
Keywords
- Biological process
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameMalate transporter MleP
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageBacteria > Bacillota > Bacilli > Lactobacillales > Streptococcaceae > Lactococcus
Accessions
- Primary accessionO07032
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Cell membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 11-31 | Helical | ||||
Sequence: GISLPLYAFFVAVIIVVTLLG | ||||||
Transmembrane | 35-55 | Helical | ||||
Sequence: LDMVGLTLLLVTLGHLLYFIG | ||||||
Transmembrane | 65-85 | Helical | ||||
Sequence: LGGGSVFTLIGATLLSFFHIV | ||||||
Transmembrane | 96-116 | Helical | ||||
Sequence: FMGGKFGFLDFYIAALICGSI | ||||||
Transmembrane | 134-154 | Helical | ||||
Sequence: IALITMVIGFFSVGLVGMLIG | ||||||
Transmembrane | 196-216 | Helical | ||||
Sequence: IFSQLAPAVTFGNILAIIGAL | ||||||
Transmembrane | 246-266 | Helical | ||||
Sequence: IKLDAQQIGTGMLFAFALLMA | ||||||
Transmembrane | 269-289 | Helical | ||||
Sequence: ILNKFFPNIHQYAFMIIIVFI | ||||||
Transmembrane | 310-330 | Helical | ||||
Sequence: VIMTNLTHAVLAGIGLALIDL | ||||||
Transmembrane | 339-359 | Helical | ||||
Sequence: WQFVVLCLTSVVVMGLASWFL | ||||||
Transmembrane | 401-421 | Helical | ||||
Sequence: FAQMANRLCGAIVLIFGGILI |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000460555 | 1-425 | Malate transporter MleP | |||
Sequence: MKKLKETKISGISLPLYAFFVAVIIVVTLLGKLPLDMVGLTLLLVTLGHLLYFIGEKFPIMNSYLGGGSVFTLIGATLLSFFHIVPSNVIGAVSNFMGGKFGFLDFYIAALICGSILGMNRNLLVKASKKFIPIALITMVIGFFSVGLVGMLIGNGFADSVMYVSMPMMSGGMGAGITPLSQIYAAGLAHGNQAAIFSQLAPAVTFGNILAIIGALSIAKVFNKSKYNGHGTLVAATKEELAKPKIKLDAQQIGTGMLFAFALLMAGDILNKFFPNIHQYAFMIIIVFILKATNTVPKDLEESVVMFNQVIMTNLTHAVLAGIGLALIDLNTLASAFTWQFVVLCLTSVVVMGLASWFLARLFGLYPVETAIGAGMINNSMGGTGNIAVLSASDRMEMIAFAQMANRLCGAIVLIFGGILIRFFY |
Proteomic databases
Structure
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).
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
Belongs to the 2-hydroxycarboxylate transporter (2-HCT) (TC 2.A.24) family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length425
- Mass (Da)45,309
- Last updated1997-07-01 v1
- Checksum4A435EA335352AF0
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X75982 EMBL· GenBank· DDBJ | CAA53590.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AE005176 EMBL· GenBank· DDBJ | AAK04999.1 EMBL· GenBank· DDBJ | Genomic DNA |