Sequence and phylogenetic analysis of the Borrelia burgdorferi secA gene.

A Borrelia burgdorferi secA homologue was cloned and the complete DNA sequence was determined. The deduced protein sequence consists of 899 amino acids and shows a high degree of homology to SecA homologues from other Bacteria and photosynthetic plastids. The presence of the secA gene in Spirochetes suggests that this gene is present in most if not all major lineages within Bacteria. The ease of isolation of secA by conservation of its ATP-binding motifs combined with its extreme conservation in protein secretion pathways and the presence of a phylogenetic sequence marker in one of its ATP-binding domains makes this gene useful for phylogenetic analysis of Bacteria and photosynthetic plastids.