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

Biological and computer-assisted analyses of a 25 kb fragment from Arabidop sis thaliana chromosome IV led to the characterization of two multigene fam ilies and three novel orphan genes, not previously described. The first gen e family named AtMO1-4 encodes monooxygenases, related to the prokaryotic s alicylate hydroxylases. The second gene family contains three members, two on the analysed 25 kb fragment and one on chromosome I. The latter three ge nes lack introns and are homologous to the previously studied Glycine max s rc2 gene which is overexpressed at low temperature. Gene expression and pri mary structure of the deduced proteins are described and compared. Three ge nes of unknown function, showing tissue specific expressions, are character ized on the 25 kb fragment. Full length or partial cognate cDNAs have been sequenced for all the genes studied. (C) 1999 Elsevier Science B.V. All rig hts reserved.