Funtional diversity among orthologs glycosyl tranferases from bacterila symbionts and pathogens

FERRARI, W; FISCHER, S; MORI, G; LAGARES, A; JOFRÉ, E

Huerta Grande (Córdoba)

Congreso; XVII Jornadas de la Sociedad de Biología de Córdoba; 2009

Sociedad de Biología de Córdoba

LpcC of Rhizobium leguminosarum and LpsB of Sinorhizobium meliloti are orthologs proteins sharing 58% and 72% of identity and similarity, respectively. LpsB and LpcC are glucosyl/manosyl transferases involved in the biosynthesis of Inner Core of LPS. Previous studies have shown that the gene lpcC not complemented S. meliloti lpsB mutants, while lpsB complemented R. leguminosarum lpcC mutants. Orthologs of LpsB and LpcC are present in other α- proteobacteria including B. japonicum, M. loti, A. tumefaciens and the human pathogens Brucella melitensis and Bartonella henselae. To determine if this high conservation correlates with the functionality of these proteins, lpsB and lpcC mutants were complemented by their orthologs enzymes. The results showed that lpcC of R. leguminosarum, A. tumefaciens, B. melitensis , and waaC of M. loti complemented B. japonicum lpcC mutants, restoring the LPS profile to its wild-type phenotype. On the other hand, lpsB of S. meliloti, lpcC of R. leguminosarum and B. japonicum complemented A. tumefaciens lpcC mutants. In contrast, S. meliloti lpsB mutant was not complemented by any of its orthologs, suggesting that there is a functional diversity despite the high degree of conservation of these proteins.