CLONING AND SEQUENCING OF PHENYLETHYLAMINE OXIDASE FROM ARTHROBACTER-GLOBIFORMIS AND IMPLICATION OF TYR-382 AS THE PRECURSOR TO ITS COVALENTLY BOUND QUINONE COFACTOR
K. Tanizawa et al., CLONING AND SEQUENCING OF PHENYLETHYLAMINE OXIDASE FROM ARTHROBACTER-GLOBIFORMIS AND IMPLICATION OF TYR-382 AS THE PRECURSOR TO ITS COVALENTLY BOUND QUINONE COFACTOR, Biochemical and biophysical research communications, 199(3), 1994, pp. 1096-1102
The gene of Arthrobacter globiformis encoding a quinoprotein, phenylet
hylamine oxidase, has been cloned and sequenced. In the deduced amino
acid sequence comprising 638 residues is a tetrapeptide sequence, Asn-
Tyr-Asp-Tyr, which has been found to be highly conserved in other copp
er amine oxidases. Mutation of the former Tyr (Tyr-382) of the recombi
nant enzyme into Phe resulted in the complete loss of catalytic activi
ty and disappearance of the quinone compound that is specifically dete
cted in the wild-type enzyme, suggesting that Tyr-382 is the precursor
to the covalently-bound cofactor, most probably topa quinone. Further
more, the expression of the active, quinone-containing enzyme in Esche
richia coli cells was markedly dependent on the presence of Cu2+ ions
in the culture medium, and the inactive, Cu2+-deficient enzyme produce
d without Cu2+ ions could be converted to the active quinone form by r
econstitution with Cu2+ ions. (C) 1994 Academic Press, Inc.