Email updates

Keep up to date with the latest news and content from Genome Biology and BioMed Central.

Open Badges Research news

Double-duplication evolution

William Wells

Genome Biology 2000, 1:spotlight-20000906-02  doi:10.1186/gb-spotlight-20000906-02

The electronic version of this article is the complete one and can be found online at:

Published:6 September 2000

© 2000 BioMed Central Ltd

Research news

In the 1 September Science Lang et al. argue that two single-domain biosynthetic enzymes appear to have evolved from gene duplication, followed by fusion, followed by a second gene duplication (Science 2000, 289:1546-1550). Both of the proteins, HisA and HisF, can be broken down into two half beta/alpha barrels. The four half barrels can be superimposed on each other, revealing 22% identical or similar residues. As both enzymes bind biphosphate substrates, each half barrel has a phosphate-binding motif, and HisF even exhibits limited HisA catalytic activity. Lang et al. propose that an ancestral protein motif was duplicated and fused to produce the HisA isomerase enzyme, before a second duplication and further evolution yielded the more complex HisF synthase activity.


  1. [] webcite

    Science magazine

  2. Three-dimensional profiles from residue-pair preferences: identification of sequences with beta/alpha-barrel fold.

    PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL