Poster #RP215
A structural model to RecA protein from Mycoplasma synoviae
Marbella Fonsêca*, Fabíola Carvalho**, Lucymara Agnez-Lima***
*UFRN,Natal,Brazil; **UFRN, Natal, Brazil; ***UFRN, Natal,Brazil
One of the major characteristics that allow mycoplasmas to establish chronic infection is its genomic flexibility, related with homologous recombination mediated by RecA. This highly conserved protein among bacteria is responsible for invasion and exchange of DNA filaments. This work aimed to suggest a RecA structural model from Mycoplasma synoviae (MsRecA) and to evaluate the occurrence of polymorphisms in this protein in several isolates of this specie. The RecA structure was predicted by homology modeling using structures from Escherichia coli (EcRecA) and Mycobacterium tuberculosis (MtRecA) available at PDB. The MsRecA structural model obtained conserves the main domains present in MtRecA and EcRecA. Crucial amino acids involved in ATP, ssDNA/dsDNA binding and RecA monomer interaction are conserved. In L1 and L2 loop it were found six and three amino acids substitution, respectively, which appear to unaffected the conformation and function of MsRecA. Moreover, the C-terminal domain is shorter than that found in EcRecA and MtRecA, which may increase its capacity to bind dsDNA and displace SSB, compensating the absence of recombination initiation enzymes. The MS59 isolate RecA sequence showed one polymorphism, a substitution of Val195 to Ile195, which does not affect its functions since these belong to the same physical-chemical group.