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1.B.3.1.1
LamB (MalL) maltoporin (maltose–maltoheptose).  Also catalyzes the uptake of antibiotics (Lin et al. 2014).  LamB preferentially binds maltodextrins from the periplasmic side, and thus, sugar binding and uptake are asymmetric (Mulvihill et al. 2019).

Accession Number:P02943
Protein Name:LamB aka MALB aka B4036
Length:446
Molecular Weight:49912.00
Species:Escherichia coli [83333]
Number of TMSs:1
Location1 / Topology2 / Orientation3: Cell outer membrane1 / Multi-pass membrane protein2
Substrate Maltose, Maltobiose, Maltotriose, Maltotetrose, Maltopentose, Maltohexose, Maltoheptose, antibiotics

Cross database links:

Genevestigator: P02943
EchoBASE: EB0523
EcoGene: EG10528
eggNOG: COG4580
HEGENOM: HBG309714
DIP: DIP-10082N
RefSeq: AP_004537.1    NP_418460.1   
Entrez Gene ID: 948548   
Pfam: PF02264   
Drugbank: Drugbank Link   
BioCyc: EcoCyc:EG10528-MONOMER    ECOL168927:B4036-MONOMER   
KEGG: ecj:JW3996    eco:b4036   

Gene Ontology

GO:0009279 C:cell outer membrane
GO:0005886 C:plasma membrane
GO:0046930 C:pore complex
GO:0015288 F:porin activity
GO:0005515 F:protein binding
GO:0005351 F:sugar:hydrogen symporter activity
GO:0009597 P:detection of virus
GO:0046718 P:entry of virus into host cell
GO:0006811 P:ion transport
GO:0015768 P:maltose transport

References (16)

[1] “Gene sequence of the lambda receptor, an outer membrane protein of E. coli K12.”  Clement J.M.et.al.   6086106
[2] “Analysis of the Escherichia coli genome. IV. DNA sequence of the region from 89.2 to 92.8 minutes.”  Blattner F.R.et.al.   8265357
[3] “The complete genome sequence of Escherichia coli K-12.”  Blattner F.R.et.al.   9278503
[4] “Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110.”  Hayashi K.et.al.   16738553
[5] “Sequence determinants in the lamB gene of Escherichia coli influencing the binding and pore selectivity of maltoporin.”  Heine H.G.et.al.   3301537
[6] “DNA sequence encoding the signal peptide of the lambda receptor in E. coli K 12.”  Clement J.M.et.al.   161974
[7] “DNA sequence encoding the NH2-terminal peptide involved in transport of lambda receptor, an Escherichia coli secretory protein.”  Hedgpeth J.et.al.   6446717
[8] “Genetic analysis of sequences in maltoporin that contribute to binding domains and pore structure.”  Heine H.G.et.al.   2832377
[9] “Role of a disulfide bond in the thermal stability of the LamB protein trimer in Escherichia coli outer membrane.”  Luckey M.et.al.   1988451
[10] “Permissive sites and topology of an outer membrane protein with a reporter epitope.”  Charbit A.et.al.   1702781
[11] “A model of maltodextrin transport through the sugar-specific porin, LamB, based on deletion analysis.”  Klebba P.E.et.al.   7925308
[12] “Sucrose transport through maltoporin mutants of Escherichia coli.”  Van Gelder P.et.al.   11742115
[13] “Protein complexes of the Escherichia coli cell envelope.”  Stenberg F.et.al.   16079137
[14] “Structural basis for sugar translocation through maltoporin channels at 3.1-A resolution.”  Schirmer T.et.al.   7824948
[15] “Crystal structures of various maltooligosaccharides bound to maltoporin reveal a specific sugar translocation pathway.”  Dutzler R.et.al.   8805519
[16] “Channel specificity: structural basis for sugar discrimination and differential flux rates in maltoporin.”  Wang Y.-F.et.al.   9299337
Structure:
1AF6   1MAL   1MPM   1MPN   1MPO   1MPQ     

External Searches:

  • Search: DB with
  • BLAST ExPASy (Swiss Institute of Bioinformatics (SIB) BLAST)
  • CDD Search (Conserved Domain Database)
  • Search COGs (Clusters of Orthologous Groups of proteins)
  • 2° Structure (Network Protein Sequence Analysis)

Analyze:

Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence
1:	MMITLRKLPL AVAVAAGVMS AQAMAVDFHG YARSGIGWTG SGGEQQCFQT TGAQSKYRLG 
61:	NECETYAELK LGQEVWKEGD KSFYFDTNVA YSVAQQNDWE ATDPAFREAN VQGKNLIEWL 
121:	PGSTIWAGKR FYQRHDVHMI DFYYWDISGP GAGLENIDVG FGKLSLAATR SSEAGGSSSF 
181:	ASNNIYDYTN ETANDVFDVR LAQMEINPGG TLELGVDYGR ANLRDNYRLV DGASKDGWLF 
241:	TAEHTQSVLK GFNKFVVQYA TDSMTSQGKG LSQGSGVAFD NEKFAYNINN NGHMLRILDH 
301:	GAISMGDNWD MMYVGMYQDI NWDNDNGTKW WTVGIRPMYK WTPIMSTVME IGYDNVESQR 
361:	TGDKNNQYKI TLAQQWQAGD SIWSRPAIRV FATYAKWDEK WGYDYTGNAD NNANFGKAVP 
421:	ADFNGGSFGR GDSDEWTFGA QMEIWW