SSU71, ENCODING THE LARGEST SUBUNIT OF TFIIF, IS LOCATED ON THE RIGHTARM OF CHROMOSOME-VII IN SACCHAROMYCES-CEREVISIAE

SSU71 (TFG1) is an essential nuclear gene encoding the largest subunit of the yeast general transcription factor TFIIF. The SSU71 gene was p hysically mapped to the right arm of chromosome VII, physically linked to QCR9, by hybridization of the cloned gene to CHEF and lambda clone grid blots. This assignment was confirmed by genetic mapping. A searc h of the nucleotide sequence databases revealed that SSU71 is immediat ely adjacent to the TYS1 gene, which encodes tRNA(Tyr) synthetase. TYS 1 was reported previously to lie on chromosome XV based on sequence ov erlap with the adjacent UBR1 gene. The mapping data reported here esta blished that TYS1 and UBR1 do not lie on chromosome XV; rather the SSU 71-TYS1-UBR1 gene cluster lies on the right arm of chromosome VII, phy sically linked to QCR9 and genetically linked to ade3 and ser2.