Molecular evolution of the histidine biosynthetic pathway

摘要: The available sequences of genes encoding the enzymes associated with histidine biosynthesis suggest that this is an ancient metabolic pathway was assembled prior to diversification Bacteria, Archaea, and Eucarya. Paralogous duplications, gene elongation, fusion events involving different his have played a major role in shaping biosynthetic route. Evidence hisA hisF their homologues are result two successive duplication apparently took place before separation three cellular lineages extended. These as well homology between hisH TrpG-type amidotransferases support idea during early stages evolution at least parts were mediated by broader substrate specificities. Maximum likelihood trees calculated for these been obtained. Their topologies possibility evolutionary proximity archaebacteria low GC Gram-positive bacteria. This observation consistent those detected other workers using heat-shock proteins (HSP70), glutamine synthetases, glutamate dehydrogenases, carbamoylphosphate synthetases.