Lipid modification of the Cu,Zn superoxide dismutase from Mycobacterium tuberculosis

• Published in: Biochemical journal 2001-10, Vol.359 (Pt 1), p.17-22
• Main Authors: D'orazio, M, Folcarelli, S, Mariani, F, Colizzi, V, Rotilio, G, Battistoni, A
• Format: Article
• Language: English
• Subjects: Cell Membrane - metabolism; DNA Primers - chemistry; Escherichia coli - enzymology; Escherichia coli Proteins; Humans; Macrophages - cytology; Macrophages - microbiology; Mycobacterium tuberculosis; Mycobacterium tuberculosis - enzymology; Mycobacterium tuberculosis - genetics; Palmitic Acid - metabolism; Peptide Fragments - chemistry; Peptide Fragments - metabolism; Phagocytosis; Polymerase Chain Reaction; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Up-Regulation
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/0264-6021:3590017

The leader sequence of Mycobacterium tuberculosis Cu,Zn superoxide dismutase (Cu,ZnSOD) contains a prokaryotic membrane lipoprotein attachment site. In the present study, we have found that the protein, which exhibits detectable SOD activity, is lipid-modified and associated with the bacterial membrane when expressed either in M. tuberculosis or in Escherichia coli. These results provide the first demonstration of lipid modification of a Cu,ZnSOD. An analysis of the sodC genes present in available databases indicates that the same signal for lipid modification is also present in the sodC gene products from other mycobacteria and Gram-positive bacteria and, uniquely, in two distinct sodC gene products from the Gram-negative bacterium Salmonella typhimurium. Evidence is also provided for an up-regulation of M. tuberculosis sodC in response to phagocytosis by human macrophages, suggesting that Cu,ZnSOD is involved in the mechanisms that facilitate mycobacterial intracellular growth.