Received April 21, 2010
Unlike mammalian NO synthases, bacterial NO synthases do not contain a reductase domain. The only exception from this rule is the NO synthase from myxobacterium Sorangium cellulosum, but its reductase domain has unusual structure and location in the enzyme molecule. Recent achievements in bacterial genome sequencing have revealed the gene coding NO synthase (represented as an oxygenase domain) in some bacteria and have advanced the study of structure and functions of bacterial NO synthases. Important features of structure, sources of reducing equivalents, evolutionary connections, and functions of bacterial NO synthases (i.e. participation in nitration of the indole ring of Trp, in reparation of UV-radiation damage, role in adaptation of bacteria to oxidative stress, participation in the synthesis of cGMP, and resistance of bacteria against antibiotics) are described.
KEY WORDS: NO synthase, nitric oxide, oxygenase domain, bacteria