Skip to main content
Log in

Base Composition Skews, Replication Orientation, and Gene Orientation in 12 Prokaryote Genomes

  • Published:
Journal of Molecular Evolution Aims and scope Submit manuscript

Abstract.

Variation in GC content, GC skew and AT skew along genomic regions was examined at third codon positions in completely sequenced prokaryotes. Eight out of nine eubacteria studied show GC and AT skews that change sign at the origin of replication. The leading strand in DNA replication is G-T rich at codon position 3 in six eubacteria, but C-T rich in two Mycoplasma species. In M. genitalium the AT and GC skews are symmetrical around the origin and terminus of replication, whereas its GC content variation has been shown to have a centre of symmetry elsewhere in the genome. Borrelia burgdorferi and Treponema pallidum show extraordinary extents of base composition skew correlated with direction of DNA replication. Base composition skews measured at third codon positions probably reflect mutational biases, whereas those measured over all bases in a sequence (or at codon positions 1 and 2) can be strongly affected by protein considerations due to the tendency in some bacteria for genes to be transcribed in the same direction that they are replicated. Consequently in some species the direction of skew for total genomic DNA is opposite to that for codon position 3.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Additional information

Received: 2 February 1998 / Accepted: 15 June 1998

Rights and permissions

Reprints and permissions

About this article

Cite this article

McLean, M., Wolfe, K. & Devine, K. Base Composition Skews, Replication Orientation, and Gene Orientation in 12 Prokaryote Genomes. J Mol Evol 47, 691–696 (1998). https://doi.org/10.1007/PL00006428

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/PL00006428

Navigation