A structural comparison of molybdenum cofactor-containing enzymes

This work gives an overview of the recent achievements which have contribut ed to the understanding of the structure and Function of molybdenum and tun gsten enzymes. Known structures of molybdo-pterin cofactor-containing enzym es will be described briefly and the structural differences between represe ntatives of the same and different families will be analyzed. This comparis on will show that the molybdo-pterin cofactor-containing enzymes represent a very heterogeneous group with differences in overall enzyme structure, co factor composition and stoichiometry, as well as differences in the immedia te molybdenum environment. Two recently discovered molybdo-pterin cofactor- containing enzymes will be described with regard to molecular and EPR spect roscopic properties, pyrogallol-phloroglucinol transhydroxylase from Peloba cter acidigallici and acetylene hydratase from Pelobacter acetylenicus. On the basis of its amino acid sequence, transhydroxylase can be classified as a member of the dimethylsulfoxide reductase family, whereas classification of the tungsten/molybdenum-containing acetylene hydratase has to await the determination of its amino acid sequence. (C) 1999 Published by Elsevier S cience B.V. All rights reserved.