Phylogenetic Distribution and Diversity of Bacterial Pseudo-Orthocaspases Underline Their Putative Role in Photosynthesis.

ABSTRACT: Orthocaspases are prokaryotic caspase homologs - proteases, which cleave their substrates after positively charged residues using a conserved histidine - cysteine (HC) dyad situated in a catalytic p20 domain. However, in orthocaspases pseudo-variants have been identified, which instead of the catalytic HC residues contain tyrosine and serine, respectively. The presence and distribution of these presumably proteolytically inactive p20-containing enzymes has until now escaped attention. We have performed a detailed analysis of orthocaspases in all available prokaryotic genomes, focusing on pseudo-orthocaspases. Surprisingly we identified type I metacaspase homologs in filamentous cyanobacteria. While genes encoding pseudo-orthocaspases seem to be absent in Archaea, our results show conservat

SUBMITTER: Klemencic M 

PROVIDER: S-EPMC6426788 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature