- General bacterial porin family
Symbol = Porin_1
Name = Gram-negative porin
PROSITE = PDOC00498
SCOP = 1mpf
TCDB = 1.B.1
OPM family= 31
OPM protein= 1pho
PDB=PDB3|2fgrA:21-351 PDB3|2fgqX:20-351PDB3|1pho :27-351 PDB3|1iivA:27-378 PDB3|1osmA:27-363PDB3|1opfD:28-362 PDB3|1mpf :28-362 PDB3|2omf :28-362PDB3|1gfm :28-362 PDB3|1hxuA:28-362 PDB3|1gfp :28-362PDB3|1gfq :28-362 PDB3|1hxxA:28-362 PDB3|1bt9A:28-362PDB3|1gfo :28-362 PDB3|1gfn :28-362 PDB3|1hxtA:28-362
General bacterial porins are a family of proteins from the outer membrane of
Gram-negative bacteriaacts. The porins act as molecular filters for hydrophiliccompoundscite journal |author=Benz R, Bauer K |title=Permeation of hydrophilic molecules through theouter membrane of gram-negative bacteria. Review on bacterial porins |journal=Eur. J. Biochem. |volume=176 |issue=1 |pages=1–19 |year=1988 |pmid=2901351 |doi=10.1111/j.1432-1033.1988.tb14245.x] . They are responsible for the 'molecular sieve' properties of the outer membrane. Porins form large water-filled channels which allows the diffusion of hydrophilic molecules into the periplasmic space. Some porins form general diffusion channels that allows any solutes up to a certain size (that size is known as the exclusion limit) to cross the membrane, while other porins are specific for a solute and contain a binding site for that solute inside the pores (these are known as selective porins). As porins are the major outer membrane proteins, they also serve as receptor sites for the binding of phagesand bacteriocins.
General diffusion porins generally assemble as trimer in the membrane and the transmembrane core of these proteins is composed exclusively of beta strandscite journal |author=Jap BK, Walian PJ |title=Biophysics of the structure and function of porins |journal=Q. Rev. Biophys. |volume=23 |issue=4 |pages=367–403 |year=1990 |pmid=2178269] . It has been showncite journal |author=Pattus F, Jeanteur D, Lakey JH |title=The bacterial porin superfamily: sequence alignment and structure prediction |journal=Mol. Microbiol. |volume=5 |issue=9 |pages=2153–2164 |year=1991 |pmid=1662760 |doi=10.1111/j.1365-2958.1991.tb02145.x] that a number of general porins are evolutionary related, these porins are:
* Enterobacteria PhoE, OmpC, OmpF, NmpC.
Bacteriophage PA-2" LC.
* Neisseria PI.A, PI.B
Porin, Neisseria sp. typeInterPro|IPR002299
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