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Reviewed, UniProtKB/Swiss-Prot P02943 (LAMB_ECOLI)

Last modified November 24, 2009. Version 110. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data | Customize display text xml rdf/xml gff fasta
Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Binary interactions · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents

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Names and origin

Protein namesRecommended name:
    Maltoporin
Alternative name(s):
    Maltose-inducible porin
    Lambda receptor protein
Gene names
Name: lamB
Synonyms: malB
Ordered Locus Names: b4036, JW3996
OrganismEscherichia coli (strain K12) [Complete proteome] [HAMAP]
Taxonomic identifier83333 [NCBI]
Taxonomic lineageBacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

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Protein attributes

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

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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 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.

Induction

By maltose. HAMAP MF_01301

Sequence similarities

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

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Binary interactions

With

Entry

#Exp.

IntAct

Notes

secAP104082EBI-371309,EBI-543213

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Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

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

Regions

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

Sites

Site311Greasy slide, important in sugar transport HAMAP MF_01301
Site661Greasy slide, important in sugar transport HAMAP MF_01301
Site991Greasy slide, important in sugar transport HAMAP MF_01301
Site1431Important in sugar transport HAMAP MF_01301
Site2521Greasy slide, important in sugar transport HAMAP MF_01301
Site3831Greasy slide, important in sugar transport HAMAP MF_01301
Site4451Greasy slide, important in sugar transport HAMAP MF_01301

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

1 ........................................................... 446
Helix Strand Turn

Details...

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Sequences

Sequence LengthMass (Da)Tools
P02943-1 [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

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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: 6086106] [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: 8265357] [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: 9278503] [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: 16738553] [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: 3301537] [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: 161974] [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: 6446717] [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: 2832377] [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: 1988451] [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: 1702781] [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: 7925308] [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: 11742115] [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: 16079137] [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: 7824948] [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: 8805519] [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: 9299337] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS).

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Cross-references

Sequence databases

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.
RefSeqAP_004537.1.
NP_418460.1.

3D structure databases

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[»]
ModBaseSearch...

Protein-protein interaction databases

DIPDIP:10082N.
IntActP02943. 3 interactions.
STRINGP02943.

Protein family/group databases

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

Proteomic databases

PRIDEP02943.

Genome annotation databases

GeneID948548.
GenomeReviewsGene locus JW3996 in contig AP009048_GR.
Gene locus b4036 in contig U00096_GR.
KEGGecj:JW3996.
eco:b4036.

Organism-specific databases

EchoBASEEB0523.
EcoGeneEG10528. lamB.
CMRSearch...

Phylogenomic databases

HOGENOMP02943.
OMANVKSQRT

Enzyme and pathway databases

BioCycEcoCyc:EG10528-MON.
ECOL168927:B4036-MON.

Gene expression databases

GenevestigatorP02943.

Family and domain databases

HAMAPMF_01301.
[Tree]
InterProIPR003192. Porin_LamB.
[Graphical view]
Gene3DG3DSA:2.40.170.10. Porin_LamB. 1 hit.
PfamPF02264. LamB. 1 hit.
[Graphical view]
ProDomPD008788. Porin_LamB. 1 hit.
[Graphical view] [Entries sharing at least one domain]
ProtoNetSearch...

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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: November 24, 2009
This is version 110 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation projectHAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)

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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

Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Binary interactions · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents