title: Lysine succinylation of Mycobacterium tuberculosis isocitrate lyase (ICL) fine-tunes the microbial resistance to antibiotics.
abstract: Lysine succinylation (Ksucc) is a newly identified protein posttranslational modification (PTM), which may play an important role in cellular physiology. However, the role of lysine succinylation in antibiotic resistance remains elusive. Isocitrate lyase (ICL) is crucial for broad-spectrum antibiotics tolerance in Mycobacterium tuberculosis (Mtb). We previously found that MtbICL (Rv0467) has at least three succinylated lysine residues, namely K189, K322, and K334.To explore the effect of succinylation on the activity of MtbICL, mutants' mimicry of the lysine succinylation were generated by site-directed mutagenesis. ICL-K189E mutant strain is more sensitive than the wild-type to rifampicin and streptomycin, but not isoniazid. For the in vitro activity of the purified isocitrate lyase, only K189E mutant showed significantly decreased activity. Crystal structure analysis showed that Lys189 Glu dramatically increased the pKa of Glu188 and decreased the pKa of Lys190, whereas had negligible effect on other residues within 5 Å as well as disruption of the electrostatic interaction between Lys189 and Glu182, which might prevent the closure of the active site loop and cause severe reduction of the enzyme activity. Considering the genetic, biochemical, and crystallographical evidences together, the succinylation of specific ICL residue can fine-tune the bacterial resistance to selected antibiotics. The decreased enzymatic activity resulting from the succinylation-changed electrostatic interaction might underlie this phenotype. This study provided the first insight into the link between lysine succinylation and antibiotic resistance.
authors.affiliation: a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Zhou
authors.affiliation: a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China.
authors.forename: Longxiang
authors.initials: L
authors.lastname: Xie
authors.affiliation: b State Key Laboratory of Bioorganic and Natural Products Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032 , China.
authors.forename: Zhaozhen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: b State Key Laboratory of Bioorganic and Natural Products Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032 , China.
authors.forename: Jiahai
authors.initials: J
authors.lastname: Zhou
authors.affiliation: a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xie
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000494:pharmacology; D017124:Conserved Sequence; D024881:Drug Resistance, Bacterial; D004789:Enzyme Activation; D019143:Evolution, Molecular; D023061:Gene Order; D016680:Genome, Bacterial; D023281:Genomics; D007522:Isocitrate Lyase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism*; D050296:Microbial Viability / Q000187:drug effects / Q000235:genetics; D008958:Models, Molecular; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D011487:Protein Conformation; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000995:Antitubercular Agents; D011994:Recombinant Proteins; D007522:Isocitrate Lyase; D008239:Lysine
keywords: Mycobacterium tuberculosis; antibiotics resistance; crystal structure; isocitrate lyase; lysine succinylation; site-directed mutagenesis