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Protein

Maltose/maltodextrin import ATP-binding protein MalK

Gene

malK

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Part of the ABC transporter complex MalEFGK involved in maltose/maltodextrin import. Responsible for energy coupling to the transport system.

Catalytic activityi

ATP + H2O + maltose(Out) = ADP + phosphate + maltose(In).UniRule annotation

Regions

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Nucleotide bindingi36 – 438ATPUniRule annotation

GO - Molecular functioni

  • activating transcription factor binding Source: EcoCyc
  • ATP binding Source: EcoCyc
  • maltooligosaccharide-importing ATPase activity Source: UniProtKB-HAMAP
  • maltose-transporting ATPase activity Source: EcoCyc

GO - Biological processi

  • maltodextrin transport Source: EcoCyc
  • maltose transport Source: EcoCyc
Complete GO annotation...

Keywords - Molecular functioni

Hydrolase

Keywords - Biological processi

Sugar transport, Transport

Keywords - Ligandi

ATP-binding, Nucleotide-binding

Enzyme and pathway databases

BioCyciEcoCyc:MALK-MONOMER.
ECOL316407:JW3995-MONOMER.
MetaCyc:MALK-MONOMER.
BRENDAi3.6.3.19. 2026.

Protein family/group databases

MoonProtiP68187.
TCDBi3.A.1.1.1. the atp-binding cassette (abc) superfamily.

Names & Taxonomyi

Protein namesi
Recommended name:
Maltose/maltodextrin import ATP-binding protein MalKUniRule annotation (EC:3.6.3.19UniRule annotation)
Gene namesi
Name:malKUniRule annotation
Ordered Locus Names:b4035, JW3995
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG10558. malK.

Subcellular locationi

GO - Cellular componenti

  • ATP-binding cassette (ABC) transporter complex Source: EcoCyc
  • extrinsic component of cytoplasmic side of plasma membrane Source: EcoCyc
  • maltose transport complex Source: EcoCyc
  • membrane Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Cell inner membrane, Cell membrane, Membrane

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi85 – 851A → M: Suppressor of EAA loop mutations in MalFG. 1 Publication
Mutagenesisi106 – 1061K → C: Suppressor of EAA loop mutations in MalFG. 1 Publication
Mutagenesisi114 – 1141V → C: Suppressor of EAA loop mutations in MalFG. 1 Publication
Mutagenesisi117 – 1171V → M: Suppressor of EAA loop mutations in MalFG. 1 Publication
Mutagenesisi119 – 1191E → K: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi124 – 1241A → T: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi137 – 1371G → A: Loss of maltose transport. Has greater ability to decrease mal gene expression than wild-type MalK. 1 Publication
Mutagenesisi158 – 1581D → N: Loss of maltose transport but retains ability to repress mal genes. 1 Publication
Mutagenesisi228 – 2281R → C: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi241 – 2411F → I: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi267 – 2671W → G: Normal maltose transport but constitutive mal gene expression. 1 Publication
Mutagenesisi278 – 2781G → P: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi282 – 2821S → L: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi284 – 2841G → S: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi302 – 3021G → D: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi308 – 3081E → Q: Maltose transport is affected but retains ability to interact with MalT. 1 Publication
Mutagenesisi322 – 3221S → F: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication
Mutagenesisi340 – 3401G → A: Maltose transport is affected but retains ability to interact with MalT. 1 Publication
Mutagenesisi346 – 3461G → S: Normal maltose transport but constitutive mal gene expression. 1 Publication
Mutagenesisi355 – 3551F → Y: Maltose transport is affected but retains ability to interact with MalT. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 371371Maltose/maltodextrin import ATP-binding protein MalKPRO_0000092475Add
BLAST

Proteomic databases

PaxDbiP68187.
PRIDEiP68187.

Interactioni

Subunit structurei

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.1 Publication

GO - Molecular functioni

  • activating transcription factor binding Source: EcoCyc

Protein-protein interaction databases

BioGridi4262662. 8 interactions.
DIPiDIP-47850N.
IntActiP68187. 8 interactions.
MINTiMINT-1223477.
STRINGi511145.b4035.

Structurei

Secondary structure

1
371
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi4 – 1310Combined sources
Beta strandi16 – 2611Combined sources
Beta strandi31 – 355Combined sources
Helixi42 – 498Combined sources
Beta strandi51 – 533Combined sources
Beta strandi56 – 627Combined sources
Helixi72 – 743Combined sources
Beta strandi77 – 804Combined sources
Turni82 – 854Combined sources
Beta strandi88 – 903Combined sources
Helixi92 – 965Combined sources
Helixi98 – 1025Combined sources
Helixi107 – 12014Combined sources
Helixi124 – 1263Combined sources
Helixi131 – 1333Combined sources
Helixi136 – 15015Combined sources
Beta strandi153 – 1597Combined sources
Turni160 – 1634Combined sources
Helixi166 – 18318Combined sources
Beta strandi186 – 1905Combined sources
Helixi194 – 2007Combined sources
Beta strandi202 – 2087Combined sources
Beta strandi211 – 2166Combined sources
Helixi218 – 2236Combined sources
Helixi228 – 2336Combined sources
Beta strandi234 – 2374Combined sources
Beta strandi240 – 24910Combined sources
Beta strandi254 – 2574Combined sources
Helixi261 – 2633Combined sources
Beta strandi265 – 2706Combined sources
Beta strandi280 – 2856Combined sources
Turni287 – 2893Combined sources
Helixi293 – 2953Combined sources
Beta strandi297 – 30913Combined sources
Beta strandi311 – 3199Combined sources
Beta strandi323 – 3253Combined sources
Beta strandi327 – 3337Combined sources
Beta strandi342 – 3465Combined sources
Helixi349 – 3513Combined sources
Beta strandi353 – 3553Combined sources
Beta strandi359 – 3613Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1Q12X-ray2.60A/B/C/D1-371[»]
1Q1BX-ray2.80A/B/C/D1-371[»]
1Q1EX-ray2.90A/B1-371[»]
2AWNX-ray2.30A/B/C/D1-371[»]
2AWOX-ray2.80A/B/C/D1-371[»]
2R6GX-ray2.80A/B1-371[»]
3FH6X-ray4.50A/B/C/D1-371[»]
3GD7X-ray2.70A/B/C/D219-371[»]
3PUVX-ray2.40A/B1-371[»]
3PUWX-ray2.30A/B1-371[»]
3PUXX-ray2.30A/B1-371[»]
3PUYX-ray3.10A/B1-371[»]
3PUZX-ray2.90A/B1-371[»]
3PV0X-ray3.10A/B1-371[»]
3RLFX-ray2.20A/B1-371[»]
4JBWX-ray3.91A/B/C/D1-371[»]
4KI0X-ray2.38A/B1-371[»]
ProteinModelPortaliP68187.
SMRiP68187. Positions 2-371.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP68187.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini4 – 234231ABC transporterUniRule annotationAdd
BLAST

Sequence similaritiesi

Belongs to the ABC transporter superfamily. Maltooligosaccharide importer (TC 3.A.1.1.1) family. [View classification]UniRule annotation
Contains 1 ABC transporter domain.UniRule annotation

Phylogenomic databases

eggNOGiENOG4108IJ9. Bacteria.
COG3839. LUCA.
InParanoidiP68187.
KOiK10111.
OMAiVPERCHL.
PhylomeDBiP68187.

Family and domain databases

Gene3Di2.40.50.140. 1 hit.
3.40.50.300. 1 hit.
InterProiIPR003593. AAA+_ATPase.
IPR003439. ABC_transporter-like.
IPR017871. ABC_transporter_CS.
IPR015855. ABC_transpr_MalK.
IPR008995. Mo/tungstate-bd_C_term_dom.
IPR012340. NA-bd_OB-fold.
IPR027417. P-loop_NTPase.
IPR013611. Transp-assoc_OB_typ2.
[Graphical view]
PfamiPF00005. ABC_tran. 1 hit.
PF08402. TOBE_2. 1 hit.
[Graphical view]
SMARTiSM00382. AAA. 1 hit.
[Graphical view]
SUPFAMiSSF50331. SSF50331. 1 hit.
SSF52540. SSF52540. 1 hit.
PROSITEiPS00211. ABC_TRANSPORTER_1. 1 hit.
PS50893. ABC_TRANSPORTER_2. 1 hit.
PS51245. MALK. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P68187-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MASVQLQNVT KAWGEVVVSK DINLDIHEGE FVVFVGPSGC GKSTLLRMIA
60 70 80 90 100
GLETITSGDL FIGEKRMNDT PPAERGVGMV FQSYALYPHL SVAENMSFGL
110 120 130 140 150
KLAGAKKEVI NQRVNQVAEV LQLAHLLDRK PKALSGGQRQ RVAIGRTLVA
160 170 180 190 200
EPSVFLLDEP LSNLDAALRV QMRIEISRLH KRLGRTMIYV THDQVEAMTL
210 220 230 240 250
ADKIVVLDAG RVAQVGKPLE LYHYPADRFV AGFIGSPKMN FLPVKVTATA
260 270 280 290 300
IDQVQVELPM PNRQQVWLPV ESRDVQVGAN MSLGIRPEHL LPSDIADVIL
310 320 330 340 350
EGEVQVVEQL GNETQIHIQI PSIRQNLVYR QNDVVLVEEG ATFAIGLPPE
360 370
RCHLFREDGT ACRRLHKEPG V
Length:371
Mass (Da):40,990
Last modified:October 25, 2004 - v1
Checksum:i240D58F59450F30E
GO

Sequence cautioni

The sequence CAA23582 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.Curated

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti220 – 24122ELYHY…PKMNF → AVPLSGRPFCRRIYRFAKDE L in AAB59057 (PubMed:6296778).CuratedAdd
BLAST

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J01648 Genomic DNA. Translation: AAB59057.1.
U00006 Genomic DNA. Translation: AAC43129.1.
U00096 Genomic DNA. Translation: AAC77005.1.
AP009048 Genomic DNA. Translation: BAE78037.1.
V00303 Genomic DNA. Translation: CAA23582.1. Different initiation.
PIRiB65211. MMECMK.
RefSeqiNP_418459.1. NC_000913.3.
WP_000179165.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC77005; AAC77005; b4035.
BAE78037; BAE78037; BAE78037.
GeneIDi948537.
KEGGiecj:JW3995.
eco:b4035.
PATRICi32123603. VBIEscCol129921_4150.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J01648 Genomic DNA. Translation: AAB59057.1.
U00006 Genomic DNA. Translation: AAC43129.1.
U00096 Genomic DNA. Translation: AAC77005.1.
AP009048 Genomic DNA. Translation: BAE78037.1.
V00303 Genomic DNA. Translation: CAA23582.1. Different initiation.
PIRiB65211. MMECMK.
RefSeqiNP_418459.1. NC_000913.3.
WP_000179165.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1Q12X-ray2.60A/B/C/D1-371[»]
1Q1BX-ray2.80A/B/C/D1-371[»]
1Q1EX-ray2.90A/B1-371[»]
2AWNX-ray2.30A/B/C/D1-371[»]
2AWOX-ray2.80A/B/C/D1-371[»]
2R6GX-ray2.80A/B1-371[»]
3FH6X-ray4.50A/B/C/D1-371[»]
3GD7X-ray2.70A/B/C/D219-371[»]
3PUVX-ray2.40A/B1-371[»]
3PUWX-ray2.30A/B1-371[»]
3PUXX-ray2.30A/B1-371[»]
3PUYX-ray3.10A/B1-371[»]
3PUZX-ray2.90A/B1-371[»]
3PV0X-ray3.10A/B1-371[»]
3RLFX-ray2.20A/B1-371[»]
4JBWX-ray3.91A/B/C/D1-371[»]
4KI0X-ray2.38A/B1-371[»]
ProteinModelPortaliP68187.
SMRiP68187. Positions 2-371.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4262662. 8 interactions.
DIPiDIP-47850N.
IntActiP68187. 8 interactions.
MINTiMINT-1223477.
STRINGi511145.b4035.

Protein family/group databases

MoonProtiP68187.
TCDBi3.A.1.1.1. the atp-binding cassette (abc) superfamily.

Proteomic databases

PaxDbiP68187.
PRIDEiP68187.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC77005; AAC77005; b4035.
BAE78037; BAE78037; BAE78037.
GeneIDi948537.
KEGGiecj:JW3995.
eco:b4035.
PATRICi32123603. VBIEscCol129921_4150.

Organism-specific databases

EchoBASEiEB0553.
EcoGeneiEG10558. malK.

Phylogenomic databases

eggNOGiENOG4108IJ9. Bacteria.
COG3839. LUCA.
InParanoidiP68187.
KOiK10111.
OMAiVPERCHL.
PhylomeDBiP68187.

Enzyme and pathway databases

BioCyciEcoCyc:MALK-MONOMER.
ECOL316407:JW3995-MONOMER.
MetaCyc:MALK-MONOMER.
BRENDAi3.6.3.19. 2026.

Miscellaneous databases

EvolutionaryTraceiP68187.
PROiP68187.

Family and domain databases

Gene3Di2.40.50.140. 1 hit.
3.40.50.300. 1 hit.
InterProiIPR003593. AAA+_ATPase.
IPR003439. ABC_transporter-like.
IPR017871. ABC_transporter_CS.
IPR015855. ABC_transpr_MalK.
IPR008995. Mo/tungstate-bd_C_term_dom.
IPR012340. NA-bd_OB-fold.
IPR027417. P-loop_NTPase.
IPR013611. Transp-assoc_OB_typ2.
[Graphical view]
PfamiPF00005. ABC_tran. 1 hit.
PF08402. TOBE_2. 1 hit.
[Graphical view]
SMARTiSM00382. AAA. 1 hit.
[Graphical view]
SUPFAMiSSF50331. SSF50331. 1 hit.
SSF52540. SSF52540. 1 hit.
PROSITEiPS00211. ABC_TRANSPORTER_1. 1 hit.
PS50893. ABC_TRANSPORTER_2. 1 hit.
PS51245. MALK. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiMALK_ECOLI
AccessioniPrimary (citable) accession number: P68187
Secondary accession number(s): P02914, Q2M6R9, Q47348
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: October 25, 2004
Last modified: September 7, 2016
This is version 123 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

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.

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Escherichia coli
    Escherichia coli (strain K12): entries and cross-references to EcoGene
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.