ARE THERE 2 DNA METHYLTRANSFERASE GENE FAMILIES IN PLANT-CELLS - A NEW POTENTIAL METHYLTRANSFERASE GENE ISOLATED FROM AN ARABIDOPSIS-THALIANA GENOMIC LIBRARY

Using the 1kb 3' terminal DNA fragment of the mouse methyltransferase cDNA as a probe and low stringent hybridisation conditions, a new pote ntial methyltransferase (MTase) gene family was isolated from an Arabi dopsis thaliana genomic DNA library. One clone (MTase-11), which gave the strongest signal at the Northern blot, was entirely sequenced (114 83 bp) and further characterised. Under consideration of the likely op en reading frames and our preliminary cDNA experiments we propose that the clone 11 gene encodes for an similar to 90 kD protein. As deduced form the DNA sequence this protein contains all conserved sequence mo tifs specific for the 5m cytosine MTases. MTase-11 gene expression was demonstrable in callus and during germination but not in one month ol d plants or in leaves.