Structure and expression of three src2 homologues and a novel subfamily of flavoprotein monooxygenase genes revealed by the analysis of a 25kb fragment from Arabidopsis thaliana chromosome IV.

Biological and computer-assisted analyses of a 25kb fragment from Arabidopsis thaliana chromosome IV led to the characterization of two multigene families and three novel orphan genes, not previously described. The first gene family named AtMO1-4 encodes monooxygenases, related to the prokaryotic salicylate hydroxylases. The second gene family contains three members, two on the analysed 25kb fragment and one on chromosome I. The latter three genes lack introns and are homologous to the previously studied Glycine max src2 gene which is overexpressed at low temperature. Gene expression and primary structure of the deduced proteins are described and compared. Three genes of unknown function, showing tissue specific expressions, are characterized on the 25kb fragment. Full length or partial cognate cDNAs have been sequenced for all the genes studied.