title: Enzymatic methylation of the Mycobacterium tuberculosis heparin-binding haemagglutinin.
abstract: Heparin-binding haemagglutinin (HBHA) is an important Mycobacterium tuberculosis virulence factor. It displays a complex methylation pattern in its C-terminal, functional domain, which protects this domain against proteolysis. Here, it is shown that HBHA methylation is catalysed by mycobacterial enzymes and a radio-enzymatic and a nonradioactive enzyme assay are described, based on the recognition of methylated HBHA by monoclonal antibodies. MS analysis of in vitro methylated HBHA shows a complex methylation pattern similar to that of naturally methylated HBHA. Using recombinant hybrid molecules as acceptor substrates, it was found that the N-terminal domain of HBHA is not required for recognition by the HBHA-methyltransferase(s), although it is required for in vivo methylation.
authors.affiliation: INSERM U629, Lille, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Host
authors.forename: Hervé
authors.initials: H
authors.lastname: Drobecq
authors.forename: Camille
authors.initials: C
authors.lastname: Locht
authors.forename: Franco D
authors.initials: FD
authors.lastname: Menozzi
mesh_terms: D004926:Escherichia coli / Q000378:metabolism; D037102:Lectins / Q000378:metabolism*; D013058:Mass Spectrometry; D008745:Methylation; D008780:Methyltransferases / Q000032:analysis / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D011994:Recombinant Proteins / Q000032:analysis / Q000378:metabolism
chemical_list: D037102:Lectins; D011994:Recombinant Proteins; C104578:heparin-binding hemagglutinin; D008780:Methyltransferases