Rv0518, a nutritive stress inducible GDSL lipase of Mycobacterium tuberculosis, enhanced intracellular survival of bacteria by cell wall modulation.
Rv0518, a hypothetical protein of Mycobacterium tuberculosis, was designated as possible exported protein. In-silico analysis suggested that the protein belonged to the family of GDSL lipases. In this study, rv0518 gene was cloned and expressed in E. coli followed by purification and characterization. It possessed lipolytic activity, preferably hydrolyzed pNP-decanoate at pH 9.0 and 40 °C. The enzyme was stable till 50 °C and wider pH range (5.0-11.0). The predicted active site residues, Ser-46, Asp-205, His-208, Gly-87, Asn-120 were confirmed by site directed mutagenesis. rv0518 gene expression in M. tuberculosis H37Ra was up-regulated under nutrient starvation and the protein was detected in membrane fraction. The expression of rv0518 in M. smegmatis altered the colony morphology/growth kinetics, provided resistance to SDS, lysozyme, anti-TB drugs and enhanced in vitro survival of M. smegmatis under nutritive stress. The total lipid content and trehalose dimycolate was elevated in M. smegmatis expressing rv0518 gene. The presence of Rv0518 enhanced infection ability and intracellular survival capability of M. smegmatis. Hence, Rv0518 is a cell wall associated GDSL lipase might helped bacteria to utilize glycerol/lipids for its growth as well as provided resistance to various intracellular stresses by cell wall modulation resulting in its enhanced intracellular survival.
['Kaur|Jashandeep|J|', 'Kaur|Jagdeep|J|']
D000595:Amino Acid Sequence D018441:Biofilms D020134:Catalytic Domain D002460:Cell Line D002473:Cell Wall D003001:Cloning, Molecular D004789:Enzyme Activation D015870:Gene Expression D020869:Gene Expression Profiling D054884:Host-Pathogen Interactions D006801:Humans D006868:Hydrolysis D008049:Lipase D050356:Lipid Metabolism D008264:Macrophages D050296:Microbial Viability D008958:Models, Molecular D020102:Mycobacterium smegmatis D009169:Mycobacterium tuberculosis D011487:Protein Conformation D021381:Protein Transport D013312:Stress, Physiological D013329:Structure-Activity Relationship D013379:Substrate Specificity D000074084:THP-1 Cells D014376:Tuberculosis
GDSL lipase Mycobacterium tuberculosis Cell wall modulation Lipolytic enzyme SGNH hydrolase