In-silico analysis of genomic distribution and functional association of hipBA toxin-antitoxin (TA) homologs in entomopathogen Xenorhabdus nematophila

Abstract

• Presence of three hipBA TA paralogs in the genome of X. nematophila. • HipA homologs represents a class of serine/threonine-protein kinase. • HipB homologs represents a class of transcriptional regulator. • hipBA TA paralogs in the genome of X. nematophila are functionally associated. Bacteria have a particular strategy to invade the host immune system by forming an undetectable dormant state that may resuscitate and cause disease even after inhabiting for years in a host body. Several mechanisms are known to be responsible for bacterial dormancy, among them the hipBA toxin-antitoxin (TA) system which was initially identified in Escherichia coli . Here we explore the genomic distribution and functional association of hipBA TA homologs from an entomopathogenic bacterium Xenorhabdus nematophila . This bacterium is a symbiotic model with the nematode Steinernema carpocapsae . We found that HipA toxin homologs are more closely related than HipB antitoxins and have satisfactory adenine (for HipA homologs) and nucleic acid (for HipB homologs) ligand partners with a typical TA interaction network that may promote the X. nematophila towards a stringent response to form the dormant state. Such homologs distribution is an inclusion in the current TA repertoire of X. nematophila .