首页 | 本学科首页   官方微博 | 高级检索  
     


A functional analysis of the repeated methionine initiator tRNA genes (IMT) in yeast
Authors:Anders S. Byströ  m  Gerald R. Fink
Affiliation:(1) Whitehead Institute, Nine Cambridge Center, 02142 Cambridge, MA, USA;(2) Present address: Department of Microbiology, Umeå University, S-901 87 Umeå, Sweden
Abstract:Summary Standard laboratory yeast strains have from four to five genes encoding the methionine initiator tRNA (IMT). Strain S288C has four IMT genes with identical coding sequences that are colinear with the RNA sequence of tRNAIMet. Each of the four IMT genes from strain S288C is located on a different chromosome. A fifth IMT gene with the same coding sequence is present in strain A364A but not in S288C. By making combinations of null alleles in strain S288C, we show that each of the four IMT genes is functional and that tRNAIMetis not limiting in yeast strains with three or more intact genes. Strains containing a single IMT2, 3 or 4 gene grow only after amplification of the remaining IMT gene. Strains with only the IMT1 gene intact are viable but grow extremely slowly; normal growth is restored by the addition of another IMT gene by transformation, providing a direct test for IMT function.Abbreviations IMT and imt (imt=initiator methionine tRNA), designate the genotype of the wild-type and the mutant alleles respectively, of the initiator methionine transfer RNA gene - met-tRNAIMet methionylated initiator methionine transfer RNA - eIF-2 eukaryotic initiation factor two - GTP guanosine 5prime-triphosphateThe calculation of Td values (the temperature at which half of the duplex is dissociated) for oligonucleotides used as probes in hybridizations was based on the assumption that the increase in Td value was 4° C for each G:C base pair and 2° C for each A:T base pair (Wallace et al. 1981)
Keywords:Methionine  Initiator tRNA  tRNA(met)  Yeast  Multigene family
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号