The Evolution of Sedolisins in Eukaryotes, Bacteria and Archaea.

IRAZOQUI, M; ORTS, F; TEN HAVE A

Rosario

Congreso; 4th International Conference of Iberoamericand Society of Bioinformatcis and 4th Congress of the Asocación Argentina de Bioinformática y Biología Computacional; 2013

Asocación Argentina de Bioinformática y Biología Computacional

Proteases are enzymes that catalyze the hydrolysis of peptides. They are classified into different classes onthe basis of their catalytic mechanism and further into about 50 clans and numerous families on the basis ofsimilarity. Subtilisins and Sedolisins are homologous serine proteases. Where the basic subtilisins have thecatalytic triad of His-Asp-Ser, the sedolisins family have the triad Glu-Asp-Ser and are most active at pH 3,unique among serine proteases. Although the sedolisin activity was first described in 2001, sedolisinhomologues have been identified in all three superkingdoms. In addition, a novel subfamily was recentlysuggested to have evolved in bacteria [1]. It has been shown that the fungus Aspergillus fumigatus secretes atleast three sedolisins with tripeptidyl-carboxyl peptidase activity and one with endoprotease activity. Initialstudies on Botrytis cinerea have shown it encodes for seven sedolisins, three more as compared with otherphytopathogens, which might be related to that the fact that it acidifies its medium and has been shown todepend on other acid hydrolases. Interestingly it has relatively few subtilisins. All facts together makesedolisins an interesting subject for molecular evolutionary studies in general and structure-functionprediction analysis in particular. Here we present the first data on our analysis of real sedolisns.Materials and methodsSequence mining(Fig 1A) was performed using iterative HMMer profiling with profiles made on threeMSAs. A first MSA consisting a eukaryotic sedolisins was obtained from MEROPs, the peptidase database.Then, a secondMSA, was made of bacterial sequences obtained from Siezen et al., 2007 [1]. HMMerprofiling was performed against 450 complete proteomes, including Archaea, Bacteria and Eukaryotes.MSAs for the standard sedolisins were made with T-coffee, MAFFT, ProbCons and Promals3D and the bestMSA was manually improved and subsequently trimmed with BMGE prior to phylogeny by PhyML.ResultsApproximately 800 sedolisins were identified in the iterative HMMer profiling search. 60% of thesequences belong to Bacteria (78 species), 30 % to Eukaryota (96 species) and 10 % to Archaea (23species). Hence, sedolisins do form a superfamily. Phylogeny (Fig. 1B) shows that three to four sedolisinsubfamilies are present in all three superkingdoms The topology suggests that sedolisins have evolvedtowards a superfamily after the bifurcation of eukaryotes and prokaryotes. Based on the obtained MSA andphylogeny we will perform structure function analysis initially be directed at the identification of the endoandtripeptidyl activities and the possibility of convergent evolution.