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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)DescriptionActionsGraphical viewLength
Nucleotide bindingi36 – 43ATPUniRule annotation8

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 lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
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)DescriptionActionsGraphical viewLength
Mutagenesisi85A → M: Suppressor of EAA loop mutations in MalFG. 1 Publication1
Mutagenesisi106K → C: Suppressor of EAA loop mutations in MalFG. 1 Publication1
Mutagenesisi114V → C: Suppressor of EAA loop mutations in MalFG. 1 Publication1
Mutagenesisi117V → M: Suppressor of EAA loop mutations in MalFG. 1 Publication1
Mutagenesisi119E → K: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi124A → T: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi137G → A: Loss of maltose transport. Has greater ability to decrease mal gene expression than wild-type MalK. 1 Publication1
Mutagenesisi158D → N: Loss of maltose transport but retains ability to repress mal genes. 1 Publication1
Mutagenesisi228R → C: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi241F → I: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi267W → G: Normal maltose transport but constitutive mal gene expression. 1 Publication1
Mutagenesisi278G → P: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi282S → L: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi284G → S: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi302G → D: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi308E → Q: Maltose transport is affected but retains ability to interact with MalT. 1 Publication1
Mutagenesisi322S → F: Resistant to inhibitory effects of alpha-methylglucoside but retains transport capacity. 1 Publication1
Mutagenesisi340G → A: Maltose transport is affected but retains ability to interact with MalT. 1 Publication1
Mutagenesisi346G → S: Normal maltose transport but constitutive mal gene expression. 1 Publication1
Mutagenesisi355F → Y: Maltose transport is affected but retains ability to interact with MalT. 1 Publication1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000924751 – 371Maltose/maltodextrin import ATP-binding protein MalKAdd BLAST371

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 interactors.
DIPiDIP-47850N.
IntActiP68187. 8 interactors.
MINTiMINT-1223477.
STRINGi511145.b4035.

Structurei

Secondary structure

1371
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi4 – 13Combined sources10
Beta strandi16 – 26Combined sources11
Beta strandi31 – 35Combined sources5
Helixi42 – 49Combined sources8
Beta strandi51 – 53Combined sources3
Beta strandi56 – 62Combined sources7
Helixi72 – 74Combined sources3
Beta strandi77 – 80Combined sources4
Turni82 – 85Combined sources4
Beta strandi88 – 90Combined sources3
Helixi92 – 96Combined sources5
Helixi98 – 102Combined sources5
Helixi107 – 120Combined sources14
Helixi124 – 126Combined sources3
Helixi131 – 133Combined sources3
Helixi136 – 150Combined sources15
Beta strandi153 – 159Combined sources7
Turni160 – 163Combined sources4
Helixi166 – 183Combined sources18
Beta strandi186 – 190Combined sources5
Helixi194 – 200Combined sources7
Beta strandi202 – 208Combined sources7
Beta strandi211 – 216Combined sources6
Helixi218 – 223Combined sources6
Helixi228 – 233Combined sources6
Beta strandi234 – 237Combined sources4
Beta strandi240 – 249Combined sources10
Beta strandi254 – 257Combined sources4
Helixi261 – 263Combined sources3
Beta strandi265 – 270Combined sources6
Beta strandi280 – 285Combined sources6
Turni287 – 289Combined sources3
Helixi293 – 295Combined sources3
Beta strandi297 – 309Combined sources13
Beta strandi311 – 319Combined sources9
Beta strandi323 – 325Combined sources3
Beta strandi327 – 333Combined sources7
Beta strandi342 – 346Combined sources5
Helixi349 – 351Combined sources3
Beta strandi353 – 355Combined sources3
Beta strandi359 – 361Combined sources3

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB 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.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP68187.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini4 – 234ABC transporterUniRule annotationAdd BLAST231

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

Gene3Di3.40.50.300. 1 hit.
InterProiIPR003593. AAA+_ATPase.
IPR003439. ABC_transporter-like.
IPR017871. ABC_transporter_CS.
IPR015855. ABC_transpr_MalK.
IPR008995. Mo/tungstate-bd_C_term_dom.
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)DescriptionActionsGraphical viewLength
Sequence conflicti220 – 241ELYHY…PKMNF → AVPLSGRPFCRRIYRFAKDE L in AAB59057 (PubMed:6296778).CuratedAdd BLAST22

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
PDB 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.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4262662. 8 interactors.
DIPiDIP-47850N.
IntActiP68187. 8 interactors.
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

Gene3Di3.40.50.300. 1 hit.
InterProiIPR003593. AAA+_ATPase.
IPR003439. ABC_transporter-like.
IPR017871. ABC_transporter_CS.
IPR015855. ABC_transpr_MalK.
IPR008995. Mo/tungstate-bd_C_term_dom.
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: November 2, 2016
This is version 125 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.