CLONING, SEQUENCE-ANALYSIS AND EXPRESSION OF THE BASIDIOMYCETE LENTINUS-EDODES GENE UCK1, ENCODING UMP-CMP KINASE, THE HOMOLOG OF SACCHAROMYCES-CEREVISIAE URA6 GENE

Sequence analysis of the downstream region of the basidiomycete Lentin us edodes priB gene encoding a protein with a 'Zn(II)2Cys6 zinc cluste r' DNA-binding motif (Endo, H., Kajiwara, S., Tunoka, O., Shishido, K. , 1994. A novel cDNA, priBc, encoding a protein with a Zn(II)2Cys6 zin c cluster DNA-binding motif, derived from the basidiomycete Lentinus e dodes. Gene 139, 117-121) suggested the presence of a Saccharomyces ce revisiae URA6 gene homologue encoding UMP kinase. We isolated a corres ponding cDNA from a mature fruiting-body cDNA library of L. edodes. Th e nucleotide sequence of this was determined and compared with that of the genomic DNA, revealing that the URA6 gene homologue encodes 227 a mino acids (aa) and is interrupted by four small introns. The deduced aa sequence showed an overall identity of 51.1% to that of the S. cere visiae URA6 gene product. The URA6 homologue protein produced in Esche richia coli using the glutathione S-transferase gene fusion system was found to catalyze the phosphoryl transfer from ATP to UMP and CMP eff iciently and also to AMP and dCMP with lower efficiencies. Thus, the U RA6 gene homologue was designated uck1 and its product UMP-CMP kinase. Northern-blot analysis showed that the uck1 is actively transcribed i n the gill tissue of mature fruiting bodies of L. edodes, implying tha t uck1 may play a role during the formation of basidiospores occurs in the gill tissue. (C) 1998 Elsevier Science B.V. All rights reserved.