Genes of de novo pyrimidine biosynthesis from the hyperthermoacidophilic crenarchaeote Sulfolobus acidocaldarius: novel organization in a bipolar operon.

ABSTRACT: Sequencing a 8,519-bp segment of the Sulfolobus acidocaldarius genome revealed the existence of a tightly packed bipolar pyrimidine gene cluster encoding the enzymes of de novo UMP synthesis. The G+C content of 35.3% is comparable to that of the entire genome, but intergenic regions exhibit a considerably lower percentage of strong base pairs. Coding regions harbor the classical excess of purines on the coding strand, whereas intergenic regions do not show this bias. Reverse transcription-PCR and primer extension experiments demonstrated the existence of two polycistronic messengers, pyrEF-orf8 and pyrBI-orf1-pyrCD-orf2-orf3-orf4, initiated from a pair of divergent and partially overlapping promoters. The gene order and the grouping in two wings of a bipolar operon constitute a novel organ

SUBMITTER: Thia-Toong TL 

PROVIDER: S-EPMC135248 | biostudies-literature | 2002 Aug

REPOSITORIES: biostudies-literature