No abstract

The periplasmic nitrite reductase system from Escherichia coli and the extracellular Fe(III) reductase system from Shewanella oneidensis contain multihaem c-type cytochromes as electron carriers and terminal reductases. The position and orientation of the haem cofactors in multihaem cytochromes from different bacteria often show significant conservation despite different arrangements of the polypeptide chain. We propose that the decahaem cytochromes of the iron reductase system MtrA, MtrC and OmcA comprise pentahaem 'modules' similar to the electron donor protein, NrfB, from E. coli. To demonstrate this, we have isolated and characterized the N-terminal pentahaem module of MtrA by preparing a truncated form containing five covalently attached haems. UV-visible spectroscopy indicated that all five haems were low-spin, consistent with the presence of bis-His ligand co-ordination as found in full-length MtrA.

The focus of this study was to identify themes that emerged on the publicly-posted #ILookLikeAProfessor hashtag Twitter campaign during August 2015. This qualitative content analysis explored tweets (n=1,855) from www.twitter.com/#ILookLikeAProfessor. Through qualitative open and inductive coding methods, four major themes were derived from the Twitter campaign among participants: 1) discussing diversity, 2) addressing appearance, 3) identifying self, and 4) using visual support. Researchers offer ideas for future study about this campaign and hashtag activism.