Primer extension analysis. (A) Assay of transcription
initiation sites (lane PE) of the GLT1 gene, carried out
with total RNA obtained from the wild-type strain CLA1. (B)
Representative results of primer extension analysis carried out with
total RNA obtained from strain CLA1 transformed with plasmid pLOU1, -3,
-4, -6, -8, -9, -10, or -11 (lane 1) or with pLOU14, -15, -16, or -17
(lane 2). The sequence ladder was produced with the same
deoxyoligonucleotide used for the primer extension reaction (described
in Materials and Methods).