Bacterioferritin

From Wikipedia, the free encyclopedia

This article may require cleanup to meet Wikipedia's quality standards.
Please discuss this issue on the talk page or replace this tag with a more specific message.
This article has been tagged since July 2006.

Bacterioferritin (BFR) is an oligomeric protein containing both a binuclear iron centre and haem b. The tertiary and quaternary structure of BFR is very similar to that of ferritin. The physiological functions of BFR, which may be other than just iron uptake, are not clear. BFR forms a roughly spherical, hollow shell from 24 identical subunits, incorporating 12 haem groups. Iron is stored as a hydrated ferric oxide mineral in its central cavity (about 80 Å diameter). The overall complex has cubic (432) symmetry. Each subunit includes a binuclear metalbinding site (the diiron site) linking together the four major helices of the subunit, which has been identified as the ferroxidase active site.

BFR from Pseudomonas aeruginosa, unlike other BFRs, is found to contain two subunit types, which differ considerably in their amino acid sequences. A similar hetero-assembly is seen in the ferritins of higher eukaryotes.

PDB 1bfr PDB 1bcf