Seven
conserved signature indels (CSIs) were identified through genomic analyses as exclusively shared by
C. burnetii and other unnamed
Coxiella-related species in the
proteins glutamine-hydrolyzing
GMP synthase, type I
methionyl aminopeptidase,
ribonucleoside-diphosphate reductase subunit alpha,
translation initiation factor IF-3, phosphomannomutase-phosphoglucomutase, LPS export
ABC transporter ATP-binding protein, and
NADH-quinone oxidoreductase subunit G. These CSIs serve to reliably demarcate the genus from other
Legionellales species in molecular terms. Additionally, three CSIs were identified as uniquely shared between the genus
Coxiella, and two other genera belonging to the family
Coxiellaceae,
Diplorickettsia and
Rickettsiella. The absence of
Aquicella species (the remaining genus within the family
Coxiellaceae) from the shared CSIs suggests that the genera
Coxiella,
Diplorickettsia and
Rickettsiella share a common ancestor exclusive of
Aquicella. ==References==