engleski

Phylogenetic relationship of GDS(L) enzymes from Streptomycetes

Present study was initiated to explore distribution and phylogenetic relationship of GDS(L) lipolytic enzymes among Streptomyces. This group consists of diverse enzymes found in distantly related organisms, from bacteria to man. They display multifunctional properties with thioesterase, protease, arylesterase, lipase and lysophospholipase activities, and as such GDS(L) enzymes have an innovative potential for biotechnological application. Typically, homology in primary structure between family members is small, with only several short conserved motifs (Blocks I-V). These motifs contain important residues that form catalytic triad and oxyanione hole, e.g. catalyticaly active serine in the motif GDS(L). Our previous experimental and genome mining data showed that Streptomyces could be a good source of these enzymes most likely because of their specific and complex life style. Streptomycetes are ubiquitous Gram-positive bacteria living predominantly as saprophytes in soil. The aim of this study was to explore, for the first time, diversity and determine phylogenetic relationship of GDS(L) enzymes in streptomycetes. Similar study of GDS(L) family has been recently performed only in several land plants, and the lack of information for other organisms could be ascribed to the low overall sequence homology. To retrieve the maximal number of GDS(L) sequences from the databases, we have developed a new posterior decoding algorithm which searches for short conserved motifs. By this approach, we have found numerous GDS(L) enzymes, among which 14% was previously annotated as GDS(L) members. This analysis pointed out some interesting variations of the motifs that have to be further examined. The number and position of GDS(L) genes in the Streptomyces genomes demonstrates their importance for these bacteria - there were between 7 and 17 GDS(L) sequences spread through both essential and non-essential regions of the genome. Phylogenetic analysis divided these enzymes in 6 groups, showing that all previously explored enzymes are clustered.

phylogeny; GDS(L) family; Streptomycetes

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