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Protein

Maltoporin

Gene

lamB

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

Functioni

Involved in the transport of maltose and maltodextrins, indispensable for translocation of dextrins containing more than three glucosyl moieties. A hydrophobic path ("greasy slide") of aromatic residues serves to guide and select the sugars for transport through the channel. Also acts as a receptor for several bacteriophages including lambda.

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sitei31 – 311Greasy slide, important in sugar transport
Sitei66 – 661Greasy slide, important in sugar transport
Sitei99 – 991Greasy slide, important in sugar transport
Sitei143 – 1431Important in sugar transport
Sitei252 – 2521Greasy slide, important in sugar transport
Sitei383 – 3831Greasy slide, important in sugar transport
Sitei445 – 4451Greasy slide, important in sugar transport

GO - Molecular functioni

  • maltodextrin transmembrane transporter activity Source: EcoCyc
  • maltose transporting porin activity Source: InterPro
  • porin activity Source: CACAO
  • virus receptor activity Source: UniProtKB-KW

GO - Biological processi

  • cellular response to DNA damage stimulus Source: EcoliWiki
  • ion transport Source: UniProtKB-KW
  • maltodextrin transport Source: EcoCyc
  • transmembrane transport Source: GOC
Complete GO annotation...

Keywords - Molecular functioni

Host cell receptor for virus entry, Porin, Receptor

Keywords - Biological processi

Host-virus interaction, Ion transport, Sugar transport, Transport

Enzyme and pathway databases

BioCyciEcoCyc:EG10528-MONOMER.
ECOL316407:JW3996-MONOMER.
MetaCyc:EG10528-MONOMER.

Protein family/group databases

TCDBi1.B.3.1.1. the sugar porin (sp) family.

Names & Taxonomyi

Protein namesi
Recommended name:
Maltoporin
Alternative name(s):
Lambda receptor protein
Maltose-inducible porin
Gene namesi
Name:lamB
Synonyms:malB
Ordered Locus Names:b4036, JW3996
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG10528. lamB.

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini26 – 261Periplasmic
Transmembranei27 – 359Beta stranded
Topological domaini36 – 6429ExtracellularAdd
BLAST
Transmembranei65 – 7814Beta strandedAdd
BLAST
Topological domaini79 – 802Periplasmic
Transmembranei81 – 9313Beta strandedAdd
BLAST
Topological domaini94 – 10411ExtracellularAdd
BLAST
Transmembranei105 – 11511Beta strandedAdd
BLAST
Topological domaini116 – 1227Periplasmic
Transmembranei123 – 1308Beta stranded
Topological domaini131 – 14818ExtracellularAdd
BLAST
Transmembranei149 – 15911Beta strandedAdd
BLAST
Topological domaini160 – 1612Periplasmic
Transmembranei162 – 17312Beta strandedAdd
BLAST
Topological domaini174 – 19118ExtracellularAdd
BLAST
Transmembranei192 – 20514Beta strandedAdd
BLAST
Topological domaini206 – 2094Periplasmic
Transmembranei210 – 22213Beta strandedAdd
BLAST
Topological domaini223 – 23412ExtracellularAdd
BLAST
Transmembranei235 – 24814Beta strandedAdd
BLAST
Topological domaini249 – 2502Periplasmic
Transmembranei251 – 26313Beta strandedAdd
BLAST
Topological domaini264 – 29027ExtracellularAdd
BLAST
Transmembranei291 – 30515Beta strandedAdd
BLAST
Topological domaini306 – 3072Periplasmic
Transmembranei308 – 32316Beta strandedAdd
BLAST
Topological domaini324 – 3263Extracellular
Transmembranei327 – 34115Beta strandedAdd
BLAST
Topological domaini342 – 3432Periplasmic
Transmembranei344 – 35916Beta strandedAdd
BLAST
Topological domaini360 – 3623Extracellular
Transmembranei363 – 37816Beta strandedAdd
BLAST
Topological domaini379 – 3857Periplasmic
Transmembranei386 – 40015Beta strandedAdd
BLAST
Topological domaini401 – 43030ExtracellularAdd
BLAST
Transmembranei431 – 44515Beta strandedAdd
BLAST
Topological domaini446 – 4461Periplasmic

GO - Cellular componenti

  • cell outer membrane Source: EcoCyc
  • integral component of cell outer membrane Source: EcoCyc
  • pore complex Source: EcoCyc
Complete GO annotation...

Keywords - Cellular componenti

Cell outer membrane, Membrane

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi33 – 331R → H: Reduces ligand affinity and pore size, no longer selective for maltodextrins. 1 Publication
Mutagenesisi99 – 991W → R: Decreases starch affinity, slightly increases maltose affinity. 1 Publication
Mutagenesisi107 – 1071R → S: Decreases maltodextrin affinity, increases sucrose binding and transport. 1 Publication
Mutagenesisi134 – 1341R → A: Considerable increase in pore size and sucrose transport, slight decrease in maltose transport; when associated with A-143. 1 Publication
Mutagenesisi134 – 1341R → D or N: Slight increase in pore size; increase in sucrose transport and slight decrease in maltose transport; when associated with D-143 and F-146. 1 Publication
Mutagenesisi143 – 1431Y → F: Increases affinity for starch and maltose, pore size and transport of maltohexaose. 2 Publications
Mutagenesisi146 – 1461D → G: Increases affinity for large dextrins. 2 Publications

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 2525Add
BLAST
Chaini26 – 446421MaltoporinPRO_0000025175Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Disulfide bondi47 ↔ 631 Publication

Keywords - PTMi

Disulfide bond

Proteomic databases

PaxDbiP02943.
PRIDEiP02943.

Expressioni

Inductioni

By maltose.

Interactioni

Subunit structurei

Homotrimer formed of three 18-stranded antiparallel beta-barrels, containing three independent channels.1 Publication

Binary interactionsi

WithEntry#Exp.IntActNotes
secAP104083EBI-371309,EBI-543213

Protein-protein interaction databases

BioGridi4262663. 252 interactions.
DIPiDIP-10082N.
IntActiP02943. 2 interactions.
STRINGi511145.b4036.

Structurei

Secondary structure

1
446
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi27 – 3913Combined sources
Beta strandi42 – 443Combined sources
Beta strandi64 – 7815Combined sources
Beta strandi81 – 9313Combined sources
Beta strandi95 – 984Combined sources
Beta strandi105 – 11511Combined sources
Beta strandi118 – 1203Combined sources
Beta strandi124 – 1307Combined sources
Beta strandi135 – 1373Combined sources
Helixi138 – 1403Combined sources
Beta strandi142 – 1454Combined sources
Beta strandi149 – 15810Combined sources
Beta strandi160 – 18021Combined sources
Helixi185 – 1873Combined sources
Beta strandi190 – 20718Combined sources
Beta strandi210 – 22112Combined sources
Beta strandi236 – 24813Combined sources
Beta strandi251 – 26111Combined sources
Helixi262 – 2643Combined sources
Turni265 – 2673Combined sources
Beta strandi277 – 2793Combined sources
Beta strandi285 – 2873Combined sources
Beta strandi292 – 30514Combined sources
Turni306 – 3083Combined sources
Beta strandi309 – 32214Combined sources
Beta strandi328 – 35831Combined sources
Turni359 – 3613Combined sources
Beta strandi364 – 38118Combined sources
Beta strandi387 – 40317Combined sources
Turni409 – 4113Combined sources
Turni413 – 4164Combined sources
Beta strandi418 – 4203Combined sources
Helixi423 – 4253Combined sources
Beta strandi432 – 44615Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1AF6X-ray2.40A/B/C26-446[»]
1MALX-ray3.10A/B/C26-446[»]
1MPMX-ray2.60A/B/C26-446[»]
1MPNX-ray3.20A/B/C26-446[»]
1MPOX-ray2.80A/B/C26-446[»]
1MPQX-ray3.00A/B/C26-446[»]
ProteinModelPortaliP02943.
SMRiP02943. Positions 26-446.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP02943.

Family & Domainsi

Sequence similaritiesi

Keywords - Domaini

Signal, Transmembrane, Transmembrane beta strand

Phylogenomic databases

eggNOGiENOG4108KDD. Bacteria.
COG4580. LUCA.
HOGENOMiHOG000218083.
KOiK02024.
OMAiYNKFVLQ.
OrthoDBiEOG63C0PN.

Family and domain databases

Gene3Di2.40.170.10. 1 hit.
HAMAPiMF_01301. LamB.
InterProiIPR023738. Maltoporin.
IPR003192. Porin_LamB.
[Graphical view]
PfamiPF02264. LamB. 1 hit.
[Graphical view]
ProDomiPD008788. Porin_LamB. 1 hit.
[Graphical view] [Entries sharing at least one domain]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P02943-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MMITLRKLPL AVAVAAGVMS AQAMAVDFHG YARSGIGWTG SGGEQQCFQT
60 70 80 90 100
TGAQSKYRLG NECETYAELK LGQEVWKEGD KSFYFDTNVA YSVAQQNDWE
110 120 130 140 150
ATDPAFREAN VQGKNLIEWL PGSTIWAGKR FYQRHDVHMI DFYYWDISGP
160 170 180 190 200
GAGLENIDVG FGKLSLAATR SSEAGGSSSF ASNNIYDYTN ETANDVFDVR
210 220 230 240 250
LAQMEINPGG TLELGVDYGR ANLRDNYRLV DGASKDGWLF TAEHTQSVLK
260 270 280 290 300
GFNKFVVQYA TDSMTSQGKG LSQGSGVAFD NEKFAYNINN NGHMLRILDH
310 320 330 340 350
GAISMGDNWD MMYVGMYQDI NWDNDNGTKW WTVGIRPMYK WTPIMSTVME
360 370 380 390 400
IGYDNVESQR TGDKNNQYKI TLAQQWQAGD SIWSRPAIRV FATYAKWDEK
410 420 430 440
WGYDYTGNAD NNANFGKAVP ADFNGGSFGR GDSDEWTFGA QMEIWW
Length:446
Mass (Da):49,912
Last modified:July 21, 1986 - v1
Checksum:iB2D4E4F120DA494E
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti35 – 351G → GSG (PubMed:2832377).Curated
Sequence conflicti208 – 2081P → PDP (PubMed:2832377).Curated
Sequence conflicti381 – 3811S → T in AAC43130 (PubMed:8265357).Curated
Sequence conflicti385 – 3851R → RDP (PubMed:2832377).Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M16643 Genomic DNA. Translation: AAA24059.1.
M26131 Genomic DNA. Translation: AAA24060.1.
V00298 Genomic DNA. Translation: CAA23575.1.
J01648 Genomic DNA. Translation: AAB59058.1.
U00006 Genomic DNA. Translation: AAC43130.1.
U00096 Genomic DNA. Translation: AAC77006.1.
AP009048 Genomic DNA. Translation: BAE78038.1.
M24997 Genomic DNA. Translation: AAC41396.1.
V00297 Genomic DNA. Translation: CAA23574.1.
PIRiA03443. QRECL.
RefSeqiNP_418460.1. NC_000913.3.
WP_000973663.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC77006; AAC77006; b4036.
BAE78038; BAE78038; BAE78038.
GeneIDi948548.
KEGGiecj:JW3996.
eco:b4036.
PATRICi32123605. VBIEscCol129921_4151.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M16643 Genomic DNA. Translation: AAA24059.1.
M26131 Genomic DNA. Translation: AAA24060.1.
V00298 Genomic DNA. Translation: CAA23575.1.
J01648 Genomic DNA. Translation: AAB59058.1.
U00006 Genomic DNA. Translation: AAC43130.1.
U00096 Genomic DNA. Translation: AAC77006.1.
AP009048 Genomic DNA. Translation: BAE78038.1.
M24997 Genomic DNA. Translation: AAC41396.1.
V00297 Genomic DNA. Translation: CAA23574.1.
PIRiA03443. QRECL.
RefSeqiNP_418460.1. NC_000913.3.
WP_000973663.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1AF6X-ray2.40A/B/C26-446[»]
1MALX-ray3.10A/B/C26-446[»]
1MPMX-ray2.60A/B/C26-446[»]
1MPNX-ray3.20A/B/C26-446[»]
1MPOX-ray2.80A/B/C26-446[»]
1MPQX-ray3.00A/B/C26-446[»]
ProteinModelPortaliP02943.
SMRiP02943. Positions 26-446.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4262663. 252 interactions.
DIPiDIP-10082N.
IntActiP02943. 2 interactions.
STRINGi511145.b4036.

Protein family/group databases

TCDBi1.B.3.1.1. the sugar porin (sp) family.

Proteomic databases

PaxDbiP02943.
PRIDEiP02943.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC77006; AAC77006; b4036.
BAE78038; BAE78038; BAE78038.
GeneIDi948548.
KEGGiecj:JW3996.
eco:b4036.
PATRICi32123605. VBIEscCol129921_4151.

Organism-specific databases

EchoBASEiEB0523.
EcoGeneiEG10528. lamB.

Phylogenomic databases

eggNOGiENOG4108KDD. Bacteria.
COG4580. LUCA.
HOGENOMiHOG000218083.
KOiK02024.
OMAiYNKFVLQ.
OrthoDBiEOG63C0PN.

Enzyme and pathway databases

BioCyciEcoCyc:EG10528-MONOMER.
ECOL316407:JW3996-MONOMER.
MetaCyc:EG10528-MONOMER.

Miscellaneous databases

EvolutionaryTraceiP02943.
PROiP02943.

Family and domain databases

Gene3Di2.40.170.10. 1 hit.
HAMAPiMF_01301. LamB.
InterProiIPR023738. Maltoporin.
IPR003192. Porin_LamB.
[Graphical view]
PfamiPF02264. LamB. 1 hit.
[Graphical view]
ProDomiPD008788. Porin_LamB. 1 hit.
[Graphical view] [Entries sharing at least one domain]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "Gene sequence of the lambda receptor, an outer membrane protein of E. coli K12."
    Clement J.M., Hofnung M.
    Cell 27:507-514(1981) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
    Strain: K12.
  2. "Analysis of the Escherichia coli genome. IV. DNA sequence of the region from 89.2 to 92.8 minutes."
    Blattner F.R., Burland V.D., Plunkett G. III, Sofia H.J., Daniels D.L.
    Nucleic Acids Res. 21:5408-5417(1993) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / MG1655 / ATCC 47076.
  3. Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / MG1655 / ATCC 47076.
  4. "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110."
    Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.
    Mol. Syst. Biol. 2:E1-E5(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
    Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
  5. "Sequence determinants in the lamB gene of Escherichia coli influencing the binding and pore selectivity of maltoporin."
    Heine H.G., Kyngdon J., Ferenci T.
    Gene 53:287-292(1987) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-156, MUTAGENESIS OF ARG-33; TRP-99; ARG-107; TYR-143 AND ASP-146.
  6. "DNA sequence encoding the signal peptide of the lambda receptor in E. coli K 12."
    Clement J.M., Hedgpeth J., Hofnung M., Jacob F.
    C. R. Hebd. Seances Acad. Sci., D, Sci. Nat. 289:1033-1036(1979) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-35.
  7. "DNA sequence encoding the NH2-terminal peptide involved in transport of lambda receptor, an Escherichia coli secretory protein."
    Hedgpeth J., Clement J.M., Marchal C., Perrin D., Hofnung M.
    Proc. Natl. Acad. Sci. U.S.A. 77:2621-2625(1980) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-35.
  8. "Genetic analysis of sequences in maltoporin that contribute to binding domains and pore structure."
    Heine H.G., Francis G., Lee K.S., Ferenci T.
    J. Bacteriol. 170:1730-1738(1988) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 26-446.
  9. "Role of a disulfide bond in the thermal stability of the LamB protein trimer in Escherichia coli outer membrane."
    Luckey M., Ling R., Dose A., Malloy B.
    J. Biol. Chem. 266:1866-1871(1991) [PubMed] [Europe PMC] [Abstract]
    Cited for: DISULFIDE BOND.
  10. "Permissive sites and topology of an outer membrane protein with a reporter epitope."
    Charbit A., Ronco J., Michel V., Werts C., Hofnung M.
    J. Bacteriol. 173:262-275(1991) [PubMed] [Europe PMC] [Abstract]
    Cited for: TOPOLOGY.
  11. "A model of maltodextrin transport through the sugar-specific porin, LamB, based on deletion analysis."
    Klebba P.E., Hofnung M., Charbit A.
    EMBO J. 13:4670-4675(1994) [PubMed] [Europe PMC] [Abstract]
    Cited for: TOPOLOGY.
  12. "Sucrose transport through maltoporin mutants of Escherichia coli."
    Van Gelder P., Dutzler R., Dumas F., Koebnik R., Schirmer T.
    Protein Eng. 14:943-948(2001) [PubMed] [Europe PMC] [Abstract]
    Cited for: MUTAGENESIS OF ARG-134; TYR-143 AND ASP-146, X-RAY CRYSTALLOGRAPHY (3.2 ANGSTROMS).
  13. Cited for: SUBUNIT, SUBCELLULAR LOCATION.
    Strain: BL21-DE3.
  14. "Structural basis for sugar translocation through maltoporin channels at 3.1-A resolution."
    Schirmer T., Keller T.A., Wang Y.-F., Rosenbusch J.P.
    Science 267:512-514(1995) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (3.1 ANGSTROMS).
  15. "Crystal structures of various maltooligosaccharides bound to maltoporin reveal a specific sugar translocation pathway."
    Dutzler R., Wang Y.-F., Rizkallah P., Rosenbusch J.P., Schirmer T.
    Structure 4:127-134(1996) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) WITH SUGAR SUBSTRATES.
  16. "Channel specificity: structural basis for sugar discrimination and differential flux rates in maltoporin."
    Wang Y.-F., Dutzler R., Rizkallah P.J., Rosenbusch J.P., Schirmer T.
    J. Mol. Biol. 272:56-63(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS).

Entry informationi

Entry nameiLAMB_ECOLI
AccessioniPrimary (citable) accession number: P02943
Secondary accession number(s): Q2M6R8
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: January 20, 2016
This is version 167 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

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.