Maltoporin
LamB porin | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
![]() Structure of maltoporin fromSalmonella typhimurium.[1] | |||||||||||
Identifiers | |||||||||||
Symbol | LamB | ||||||||||
Pfam | PF02264 | ||||||||||
InterPro | IPR003192 | ||||||||||
SCOP2 | 2mpr/SCOPe/SUPFAM | ||||||||||
TCDB | 1.B.3 | ||||||||||
OPM superfamily | 32 | ||||||||||
OPM protein | 2mpr | ||||||||||
CDD | cd01346 | ||||||||||
|
Maltoporins(orLamB porins) arebacterial outer membraneproteinsof theporinfamily.Maltoporin forms a trimeric structure which facilitates thediffusionofmaltodextrinsacross the outer membrane ofGram-negativebacteria.The membrane channel is formed by an antiparallelbeta-barrel.[2]
Most pores used for diffusion contain only 16 antiparallel strands, but maltoporin has 18. The structure of maltoporin contains long loops and short turns. The long loops are in contact with the cell exterior and the turns are in contact with theperiplasm.This channel is involved in sugar transport. The sugar initially binds to the first greasy residue withvan der Waals forces.The sugar continues through the channel by guided diffusion of the sugar along the greasy residues which form a "slide".[3]
Maltoporin's original name was LamB because it is abacteriophage lambdareceptor. This channel is specific for maltosaccharides, whose affinity for the channel increases as the length of the chain increases.[3]
References
[edit]- ^Meyer JE, Hofnung M, Schulz GE (March 1997). "Structure of maltoporin from Salmonella typhimurium ligated with a nitrophenyl-maltotrioside".J. Mol. Biol.266(4): 761–75.doi:10.1006/jmbi.1996.0823.PMID9102468.
- ^Schirmer T, Rosenbusch JP, Keller TA, Wang YF (1995). "Structural basis for sugar translocation through maltoporin channels at 3.1 A resolution".Science.267(5197): 512–514.doi:10.1126/science.7824948.PMID7824948.S2CID44587780.
- ^abRanquin, An; Van Gelder, Patrick (October 2004)."Maltoporin: sugar for physics and biology".Research in Microbiology.155(8): 611–616.doi:10.1016/j.resmic.2004.05.007.