Análisis in silico de proteínas potencialmente involucradas en la biogénesis de fimbrias en Helicobacter pylori

Background. Colonization and chronic infection with Helicobacter pylori is the major contributing factor to the development of gastric cancer. A large repertoire of adhesins has been described that contribute to the adaptation of bacteria to a specific gastric niche. As in other pathogenic bacteria, H. pylori biofilm formation is central to survival on unfavorable environments. Type IV pili or fimbriae are responsible for the adhesion of many pathogenic bacteria (e.g., Escherichia coli, Pseudomonas aeruginosa and Vibrio cholerae) to various surfaces. The aim of this study was to identify and analyze genes that might encode proteins involved in the biogenesis of fimbriae on H. pylori and characterize their expression during biofilm formation. Methods. PSI BLAST, bioinformatics and molecular tools were used as well as the NCBI database search for sequences related to protein biogenesis of fimbriae. Multiple alignments were performed using the HMMer and T-COFFEE programs. The secondary structure prediction was performed with ANTHEPROT and the tertiary structures were predicted with the I-Tasser. Results. We identified two counterparts-jhp0257 and HP0272-from protein of Campylobacter rectus and PilN Xilella fastidiosa, which is part of the machinery of assembly type IV fimbria. Similarly, proteins jhp0887 and HP0953 show homology from peptide PilA level of P. aeruginosa, and the HP0953 protein is overexpressed during the formation of the biofilm. Conclusions. H. pylori possesses proteins homologous to fimbrial protein families, specifically PilN and PilA, which join type IV fimbriae in other bacteria. The latter has a higher expression level during the initial stage of the formation of biofilm.