Adenylyl cyclase inMycobacterium tuberculosis H37Rv-A possible virulence factor

Eukaryotic-like adenylyl cyclase has been identified inMycobacterium tuberculosis H37Rv. TheM. tuberculosis adenylyl cyclase gene (cya) was cloned by complementation of a cAMP dependent expression of maltose operon in acya deletionE. coli strain. The nucleotide sequence analysis of thecya gene revealed an open reading frame that coded for 443 amino acids. A comparison ofM. tuberculosis adenylyl cyclase with the protein sequences in the data bank revealed its homology to the eukaryotic Type I and the calmodulin responsive adenylyl cyclases with an average of about 40% identical and 60% similar amino acids in the catalytic domain. The occurrence of eukaryotic-like adenylyl cyclase inM. tuberculosis suggests a role for this important enzyme in cell signaling and perhaps in the pathogenesis ofM. tuberculosis. We suggest that the human pathogenM. tuberculosis might have acquired the eukaryoticcya by a recombination event.