A structural comparison of molybdenum cofactor-containing enzymes


*Corresponding author. Tel.: +49 (7531) 882103; Fax: +49 (7531) 882966; E-mail: peter.kroneck@uni-konstanz.de


This work gives an overview of the recent achievements which have contributed to the understanding of the structure and function of molybdenum and tungsten enzymes. Known structures of molybdo-pterin cofactor-containing enzymes will be described briefly and the structural differences between representatives of the same and different families will be analyzed. This comparison will show that the molybdo-pterin cofactor-containing enzymes represent a very heterogeneous group with differences in overall enzyme structure, cofactor composition and stoichiometry, as well as differences in the immediate molybdenum environment. Two recently discovered molybdo-pterin cofactor-containing enzymes will be described with regard to molecular and EPR spectroscopic properties, pyrogallol-phloroglucinol transhydroxylase from Pelobacter 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.