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P02943 (LAMB_ECOLI) Reviewed, UniProtKB/Swiss-Prot

Last modified May 1, 2013. Version 143. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Interactions·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Maltoporin
Alternative name(s):
Lambda receptor protein
Maltose-inducible porin
Gene names
Name:lamB
Synonyms:malB
Ordered Locus Names:b4036, JW3996
OrganismEscherichia coli (strain K12) [Reference proteome] [HAMAP]
Taxonomic identifier83333 [NCBI]
Taxonomic lineageBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia

Protein attributes

Sequence length446 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

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. HAMAP-Rule MF_01301

Subunit structure

Homotrimer formed of three 18-stranded antiparallel beta-barrels, containing three independent channels. Ref.13

Subcellular location

Cell outer membrane; Multi-pass membrane protein Ref.13.

Induction

By maltose. HAMAP-Rule MF_01301

Sequence similarities

Belongs to the porin LamB (TC 1.B.3) family. [View classification]

Binary interactions

With

Entry

#Exp.

IntAct

Notes

secAP104083EBI-371309,EBI-543213

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 2525 HAMAP-Rule MF_01301
Chain26 – 446421Maltoporin HAMAP-Rule MF_01301
PRO_0000025175

Regions

Topological domain261Periplasmic Ref.10 Ref.11
Transmembrane27 – 359Beta stranded HAMAP-Rule MF_01301
Topological domain36 – 6429Extracellular Ref.10 Ref.11
Transmembrane65 – 7814Beta stranded HAMAP-Rule MF_01301
Topological domain79 – 802Periplasmic Ref.10 Ref.11
Transmembrane81 – 9313Beta stranded HAMAP-Rule MF_01301
Topological domain94 – 10411Extracellular Ref.10 Ref.11
Transmembrane105 – 11511Beta stranded HAMAP-Rule MF_01301
Topological domain116 – 1227Periplasmic Ref.10 Ref.11
Transmembrane123 – 1308Beta stranded HAMAP-Rule MF_01301
Topological domain131 – 14818Extracellular Ref.10 Ref.11
Transmembrane149 – 15911Beta stranded HAMAP-Rule MF_01301
Topological domain160 – 1612Periplasmic Ref.10 Ref.11
Transmembrane162 – 17312Beta stranded HAMAP-Rule MF_01301
Topological domain174 – 19118Extracellular Ref.10 Ref.11
Transmembrane192 – 20514Beta stranded HAMAP-Rule MF_01301
Topological domain206 – 2094Periplasmic Ref.10 Ref.11
Transmembrane210 – 22213Beta stranded HAMAP-Rule MF_01301
Topological domain223 – 23412Extracellular Ref.10 Ref.11
Transmembrane235 – 24814Beta stranded HAMAP-Rule MF_01301
Topological domain249 – 2502Periplasmic Ref.10 Ref.11
Transmembrane251 – 26313Beta stranded HAMAP-Rule MF_01301
Topological domain264 – 29027Extracellular Ref.10 Ref.11
Transmembrane291 – 30515Beta stranded HAMAP-Rule MF_01301
Topological domain306 – 3072Periplasmic Ref.10 Ref.11
Transmembrane308 – 32316Beta stranded HAMAP-Rule MF_01301
Topological domain324 – 3263Extracellular Ref.10 Ref.11
Transmembrane327 – 34115Beta stranded HAMAP-Rule MF_01301
Topological domain342 – 3432Periplasmic Ref.10 Ref.11
Transmembrane344 – 35916Beta stranded HAMAP-Rule MF_01301
Topological domain360 – 3623Extracellular Ref.10 Ref.11
Transmembrane363 – 37816Beta stranded HAMAP-Rule MF_01301
Topological domain379 – 3857Periplasmic Ref.10 Ref.11
Transmembrane386 – 40015Beta stranded HAMAP-Rule MF_01301
Topological domain401 – 43030Extracellular Ref.10 Ref.11
Transmembrane431 – 44515Beta stranded HAMAP-Rule MF_01301
Topological domain4461Periplasmic Ref.10 Ref.11

Sites

Site311Greasy slide, important in sugar transport
Site661Greasy slide, important in sugar transport
Site991Greasy slide, important in sugar transport
Site1431Important in sugar transport
Site2521Greasy slide, important in sugar transport
Site3831Greasy slide, important in sugar transport
Site4451Greasy slide, important in sugar transport

Amino acid modifications

Disulfide bond47 ↔ 63 Ref.9

Experimental info

Mutagenesis331R → H: Reduces ligand affinity and pore size, no longer selective for maltodextrins. Ref.5
Mutagenesis991W → R: Decreases starch affinity, slightly increases maltose affinity. Ref.5
Mutagenesis1071R → S: Decreases maltodextrin affinity, increases sucrose binding and transport. Ref.5
Mutagenesis1341R → A: Considerable increase in pore size and sucrose transport, slight decrease in maltose transport; when associated with A-143. Ref.12
Mutagenesis1341R → 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. Ref.12
Mutagenesis1431Y → F: Increases affinity for starch and maltose, pore size and transport of maltohexaose. Ref.5 Ref.12
Mutagenesis1461D → G: Increases affinity for large dextrins. Ref.5 Ref.12
Sequence conflict351G → GSG Ref.8
Sequence conflict2081P → PDP Ref.8
Sequence conflict3811S → T in AAC43130. Ref.2
Sequence conflict3851R → RDP Ref.8

Secondary structure

.............................................................. 446
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P02943 [UniParc].

Last modified July 21, 1986. Version 1.
Checksum: B2D4E4F120DA494E

FASTA44649,912
        10         20         30         40         50         60 
MMITLRKLPL AVAVAAGVMS AQAMAVDFHG YARSGIGWTG SGGEQQCFQT TGAQSKYRLG 

        70         80         90        100        110        120 
NECETYAELK LGQEVWKEGD KSFYFDTNVA YSVAQQNDWE ATDPAFREAN VQGKNLIEWL 

       130        140        150        160        170        180 
PGSTIWAGKR FYQRHDVHMI DFYYWDISGP GAGLENIDVG FGKLSLAATR SSEAGGSSSF 

       190        200        210        220        230        240 
ASNNIYDYTN ETANDVFDVR LAQMEINPGG TLELGVDYGR ANLRDNYRLV DGASKDGWLF 

       250        260        270        280        290        300 
TAEHTQSVLK GFNKFVVQYA TDSMTSQGKG LSQGSGVAFD NEKFAYNINN NGHMLRILDH 

       310        320        330        340        350        360 
GAISMGDNWD MMYVGMYQDI NWDNDNGTKW WTVGIRPMYK WTPIMSTVME IGYDNVESQR 

       370        380        390        400        410        420 
TGDKNNQYKI TLAQQWQAGD SIWSRPAIRV FATYAKWDEK WGYDYTGNAD NNANFGKAVP 

       430        440 
ADFNGGSFGR GDSDEWTFGA QMEIWW 

« Hide

References

« Hide 'large scale' references
[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]"The complete genome sequence of Escherichia coli K-12."
Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y.
Science 277:1453-1474(1997) [PubMed] [Europe PMC] [Abstract]
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]"Protein complexes of the Escherichia coli cell envelope."
Stenberg F., Chovanec P., Maslen S.L., Robinson C.V., Ilag L., von Heijne G., Daley D.O.
J. Biol. Chem. 280:34409-34419(2005) [PubMed] [Europe PMC] [Abstract]
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).

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
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.
PIRQRECL. A03443.
RefSeqNP_418460.1. NC_000913.2.
YP_492179.1. NC_007779.1.

3D structure databases

PDBe
RCSB PDB
PDBj
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[»]
ProteinModelPortalP02943.
SMRP02943. Positions 26-446.
ModBaseSearch...

Protein-protein interaction databases

DIPDIP-10082N.
IntActP02943. 2 interactions.
STRING511145.b4036.

Protein family/group databases

TCDB1.B.3.1.1. sugar porin (SP) family.

Proteomic databases

PRIDEP02943.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaAAC77006; AAC77006; b4036.
BAE78038; BAE78038; BAE78038.
GeneID12933669.
948548.
KEGGecj:Y75_p3923.
eco:b4036.
PATRIC32123605. VBIEscCol129921_4151.

Organism-specific databases

EchoBASEEB0523.
EcoGeneEG10528. lamB.

Phylogenomic databases

eggNOGCOG4580.
HOGENOMHOG000218083.
KOK02024.
OMADYGRANA.
ProtClustDBPRK09360.

Enzyme and pathway databases

BioCycEcoCyc:EG10528-MONOMER.
ECOL316407:JW3996-MONOMER.

Gene expression databases

GenevestigatorP02943.

Family and domain databases

Gene3D2.40.170.10. 1 hit.
HAMAPMF_01301. LamB.
InterProIPR023738. Maltoporin.
IPR003192. Porin_LamB.
[Graphical view]
PfamPF02264. LamB. 1 hit.
[Graphical view]
ProDomPD008788. Porin_LamB. 1 hit.
[Graphical view] [Entries sharing at least one domain]
ProtoNetSearch...

Other

EvolutionaryTraceP02943.

Entry information

Entry nameLAMB_ECOLI
AccessionPrimary (citable) accession number: P02943
Secondary accession number(s): Q2M6R8
Entry history
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: May 1, 2013
This is version 143 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

Escherichia coli

Escherichia coli (strain K12): entries and cross-references to EcoGene

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

SIMILARITY comments

Index of protein domains and families