Abstract: The invention provides FabH polypeptides and DNA (RNA) encoding such FabH and a procedure for producing such polypeptides by recombinant techniques. Also provided are methods for utilizing such FabH for the treatment of infection, particularly bacterial infections. Antagonists against such FabH and their use as a therapeutic to treat infections, particularly bacterial infections are also provided. Further provided are diagnostic assays for detecting diseases related to the presence of FabH nucleic acid sequences and the polypeptides in a host. Also provided are diagnostic assays for detecting polynucleotides encoding novel Fab family proteins and for detecting such polypeptides in a host.