Abstact

Mycoplasma Penetrans (Mpe) is an AIDS-related mycoplasma that is also closely related to respiratory diseases. Proteins involved in the first phase of Fe-S cluster biosynthesis in the SUF-like pathway are essential in Gram-positive bacteria because there is no redundant Fe-S cluster biosynthetic pathway in these proteins. In this study, we characterized two essential proteins: cysteine desulphurase (MpeSufS) and sulfurtransferase (MpeSufU) in Mpe, and resolved their crystal structures. Our results reveal that MpeSufS belongs to type II cysteine desulfurase, and MpeSufU is a Zn2+-containing sulfurtransferase. Residue Q342 in MpeSufS and the zinc atom in MpeSufU mediate sulfur transfer from MpeSufS to MpeSufU. Mutation of Q342 significantly impacts the cysteine desulfurase activity. This study provides new insights into the regulation of the activity of the SufS-SufU complex, which will help guide the design of drugs for the treatment of mycoplasma infections.