Volume 272, Number 42,
Issue of October 17, 1997
pp. 26318-26324
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.
The Adjacent Yeast Genes ARO4 and HIS7
Carry No Intergenic Region
(Received for publication, July 9, 1997, and in revised form, August 11, 1997)
Christoph
Springer
,
Oliver
Valerius
,
Axel
Strittmatter
and
Gerhard
H.
Braus
From the Institute of Microbiology and Genetics, Georg-August
University, Grisebachstrasse 8, D-37077 Göttingen, Germany
The region between the open reading frames of the
adjacent yeast genes ARO4 and HIS7 consists of
417 base pairs (bp). Termination of ARO4 transcription and
initiation of HIS7 transcription has to take place within
this interval, because both genes are transcribed into the same
direction. We show that the ARO4 terminator and the
HIS7 promoter are spatially separated, nonoverlapping
units. The ARO4 terminator includes 84 bp of the
ARO4 3
-untranslated region with several redundant
ARO4 3
end processing signals. Deletion of the
ARO4 terminator does reduce but not completely shut down
its expression. The adjacent region of 40 bp is neither required for
correct ARO4 3
end formation nor for HIS7
initiation but contains the nucleotides corresponding to the wild type
mRNA 3
ends. The following 280 bp are required for the
HIS7 promoter. Replacement of the housekeeping
ARO4 promoter by the stronger ACT1 promoter
leads to reduced HIS7 expression due to transcriptional interference. This underlines the compactness of the yeast genome carrying virtually no intergenic regions between adjacent genes.