General bacterial porin family

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Gram-negative porin
Identifiers
Symbol Porin_1
Pfam PF00267
InterPro IPR001702
PROSITE PDOC00498
SCOP 1mpf
TCDB 1.B.1
OPM family 31
OPM protein 1pho
Available PDB structures:

2fgrA:21-351 2fgqX:20-351 1pho :27-351 1iivA:27-378 1osmA:27-363 1opfD:28-362 1mpf :28-362 2omf :28-362 1gfm :28-362 1hxuA:28-362 1gfp :28-362 1gfq :28-362 1hxxA:28-362 1bt9A:28-362 1gfo :28-362 1gfn :28-362 1hxtA:28-362

General bacterial porins are a family of proteins from the outer membrane of Gram-negative bacteria acts. The porins act as molecular filters for hydrophilic compounds[1]. 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 ins ide 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 phages and bacteriocins.

General diffusion porins generally assemble as trimer in the membrane and the transmembrane core of these proteins is composed exclusively of beta strands[2]. It has been shown[3] 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

[edit] Subfamilies

[edit] References

  1. ^ Benz R, Bauer K (1988). "Permeation of hydrophilic molecules through the outer membrane of gram-negative bacteria. Review on bacterial porins". Eur. J. Biochem. 176 (1): 1–19. doi:10.1111/j.1432-1033.1988.tb14245.x. PMID 2901351. 
  2. ^ Jap BK, Walian PJ (1990). "Biophysics of the structure and function of porins". Q. Rev. Biophys. 23 (4): 367–403. PMID 2178269. 
  3. ^ Pattus F, Jeanteur D, Lakey JH (1991). "The bacterial porin superfamily: sequence alignment and structure prediction". Mol. Microbiol. 5 (9): 2153–2164. doi:10.1111/j.1365-2958.1991.tb02145.x. PMID 1662760. 
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