Send to

Choose Destination
Trends Genet. 2002 Jun;18(6):291-4.

Base composition bias might result from competition for metabolic resources.

Author information

Atelier de BioInformatique, Université Pierre et Marie Curie, 12, rue Cuvier, 75005 Paris, France.


The GC content of bacterial genomes varies from 25 to 75%, but the reason for this variation is unclear. Here, we show that genomes of bacteria that rely on their host for survival (obligatory pathogens or symbionts) tend to be AT rich. Furthermore, we have analysed bacterial phages, plasmids and insertion sequences, which might also be regarded as 'intracellular pathogens', and show that they too are significantly richer in AT than their hosts. We suggest that the higher energy cost and limited availability of G and C over A and T/U could be a basis for the understanding of these differences.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center