Abstract

Zhihong Xu^1,†,

Jing Tao¹,

Jinjing Ni¹,

Wei Zhao²,

Jie Lu³ and

Yu-Feng Yao^1,*

²Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China

³Department of Infectious Diseases, Shanghai Ruijin Hospital, Shanghai 200025, China

^† These authors contributed equally to this work.

Abstract  SIRT family proteins are highly conserved both in the structure and function among all the organisms, and are involved in gene silencing, DNA damage repair, cell growth and metabolism. Here, a SIRT4 homologue MSMEG_4620 was identified and characterized in Mycobacterium smegmatis. MSMEG_4620 exhibits deacetylase activity that can be activated by fatty acids. Interestingly, MSMEG_4620 also possesses auto ADP-ribosylation activity. MSMEG_4620 is modified on arginine residues as revealed by a chemical stability assay. Moreover, the auto ADP-ribosylation activity of MSMEG_4620 was found to be enhanced by ferric ion. Notably, the SIRT4 homologues are widely distributed in the genomes of environmental mycobacterial species instead of pathogenic mycobacterial species. When MSMEG_4620 was deleted in M. smegmatis, the mutant strain showed a growth defect in 7H9 minimal medium compared with the parental strain. Taken together, these results provided the characteristics of a SIRT4 homologue in prokaryotes and implicated its critical roles in the growth of environmental mycobacterial species.

Keywords   MSMEG_4620; auto ADP-ribosylation; deacetylation; SIRT4; environmental mycobacteria

Received   2015-9-6　　

Accepted  2015-9-26

Funding  This work was supported by grants from the State Key Development Programs for Basic Research of China (No. 2015CB554203), the National Natural Science Foundation of China (Nos. 31270173 and 31070114), and the Program for Professor of Special Appointment (

* Correspondence address  Tel/Fax: +86-21-64671226; E-mail: [email protected]