The second zinc atom in the matrix metalloproteinase catalytic domain is absent in the full-length enzymes: a possible role for the C-terminal domain.
Domain deletion mutants of the matrix metalloproteinases consisting of the catalytic domain only contain two zinc atoms per molecule. One is essential for catalysis, while the other may fulfil a structural role. We have analysed the zinc contents of both the full-length and the truncated mutants of prostromelysin-1 and progelatinase A and report that the second zinc atom is not present in the full-length form of the proenzymes. Thus it seems likely that the role proposed for this zinc atom in maintaining the structure of the enzyme catalytic domain is performed by the C-terminal domain in the full-length enzyme.
Willenbrock
F
F
Department of Biochemistry, Queen Mary & Westfield College, University of London, UK.
Murphy
G
G
Phillips
I R
IR
Brocklehurst
K
K
D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D004792:Enzyme Precursors / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008666:Metalloendopeptidases / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D014407:Tumor Cells, Cultured; D015032:Zinc / Q000032:analysis*
D004792:Enzyme Precursors; D008666:Metalloendopeptidases; C048047:prostromelysin; D015032:Zinc