The core domain of retrotransposon integrase in Hordeum: Predicted structure and evolution

: Suoniemi A, Tanskanen J, Pentikainen O, Johnson MS, Schulman AH

Publisher: OXFORD UNIV PRESS

: 1998

: Molecular Biology and Evolution

: MOLECULAR BIOLOGY AND EVOLUTION

: MOL BIOL EVOL

: 15

: 9

: 1135

: 1144

: 10

: 0737-4038

DOI: https://doi.org/10.1093/oxfordjournals.molbev.a026021

Propagation of long terminal repeat (LTR)-bearing retrotransposons and retroviruses requires integrase (LN, EC 2.7.7.-), encoded by the retroelements themselves, which mediates the insertion of cDNA copies back into the genome. An active retrotransposon family, BARE-1, comprises similar to 7% of the barley (Hordeum vulgare subsp. vulgare) genome. We have generated models for the secondary and tertiary structure of BARE-I IN and demonstrate their similarity to structures for human immunodeficiency virus 1 and avian sarcoma virus INs. The IN core domains were compared for 80 clones from 28 Hordeum accessions representative of the diversity of the genus. Based on the structural model, variations in the predicted, aligned translations from these clones would have minimal structural and functional effects on the encoded enzymes. This indicates that Hordeum retrotransposon IN has been under purifying selection to maintain a structure typical of retroviral INs. These represent the first such analyses for plant INs.