Comparative genomics and evolution of molybdenum utilization

The trace element molybdenum (Mo) is the catalytic component of important enzymes involved in g nitrogen, sulfur, and carbon metabolism in both prokaryotes and eukaryotes. With the exception of nitrogenase, Mo is complexed by a pterin compound thus forming the biologically active molybdenum cofactor (Moco) at the catalytic sites of molybdoenzymes. The physiological roles and biochemical functions many molybdoenzymes have been characterized. However, our understanding of the occurrence evolution of Mo utilization is limited. This article focuses on recent advances in comparative genom Mo utilization in the three domains of life. We begin with a brief introduction of Mo transport systems, Mo. the Moco biosynthesis pathway, the role of posttranslational modifications, and enzymes that utilize Then, we proceed to recent computational and comparative genomics studies of Mo utilization, including a discussion on novel Moco-binding proteins that contain the C-terminal domain of the Moco sulfurase and that are suggested to represent a new family of molybdoenzymes. As most molybdoenzymes need additional cofactors for their catalytic activity, we also discuss interactions between Mo metabolism and other trace elements and finish with an analysis of factors that may influence evolution of Mo utilization. (C) 2011 Elsevier B.V. All rights reserved.