title: Sequence and characterization of an Ehrlichia chaffeensis gene encoding 314 amino acids highly homologous to the NAD A enzyme.
abstract: DNA sequence analysis of the nadA gene of Ehrlichia chaffeensis revealed a 942 bp open reading frame with the capacity to encode 314 amino acids. The amino acid sequence of the E. chaffeensis quinolinate synthetase A (NAD/A) has 53.6% identity and 82% similarity to the NAD A of the cyanelle of Cyanophora paradoxa. Portions of the homologous genes of E. canis and E. muris were also sequenced. The amino acid sequences of the NAD A of E. canis and E. muris have 89.2% and 93.2% homology, respectively, to the NAD A of E. chaffeensis. We propose that the nadA gene may be an excellent candidate for a genetic tool for the phylogenetic study of ehrlichiae.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston 77555-0609, USA.
authors.forename: X J
authors.initials: XJ
authors.lastname: Yu
authors.forename: D H
authors.initials: DH
authors.lastname: Walker
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D018469:Ehrlichia chaffeensis / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014867:Water / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009097:Multienzyme Complexes; D014867:Water; C022512:quinolinic acid synthetase