Dynamic evolution of selenocysteine utilization in bacteria: a balance between selenoprotein loss and evolution of selenocysteine from redox active cysteine residues.

ABSTRACT:

Background

Selenocysteine (Sec) is co-translationally inserted into protein in response to UGA codons. It occurs in oxidoreductase active sites and often is catalytically superior to cysteine (Cys). However, Sec is used very selectively in proteins and organisms. The wide distribution of Sec and its restricted use have not been explained.

Results

We conducted comparative genomics and phylogenetic analyses to examine dynamics of Sec decoding in bacteria at both selenium utilization trait and selenoproteome levels. These searches revealed that 21.5% of sequenced bacteria utilize Sec, their selenoproteomes have 1 to 31 selenoproteins, and selenoprotein-rich organisms are mostly Deltaproteobacteria or Firmicutes/Clostridia. Evolutionary histories of selenoproteins suggest that C

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC1794560 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature