Joined: May 2002
|Quote (theyeti @ June 17 2003,14:41)|
|The Iwashita paper is still in press, to be published in Molecular Biology and Evolution. Will be posted here when it's available on PubMed. |
Well, it's available:
Mol Biol Evol. 2003 Sep;20(9):1556-63.
A Transposable Element-Mediated Gene Divergence that Directly Produces a Novel Type Bovine Bcnt Protein Including the Endonuclease Domain of RTE-1.
Iwashita S, Osada N, Itoh T, Sezaki M, Oshima K, Hashimoto E, Kitagawa-Arita Y, Takahashi I, Masui T, Hashimoto K, Makalowski W.
|Ruminant Bcnt protein with a molecular mass of 97 kDa (designated p97Bcnt) includes a region derived from the endonuclease domain of a retrotransposable element RTE-1. Human and mouse Bcnt proteins lack the corresponding region but have a highly conserved 82-amino acid region at the C-terminus that is not present in p97Bcnt. By screening a bovine BAC library, we found two more bcnt-related genes: human-type bcnt (h-type bcnt) and its processed pseudogene. Whereas the pseudogene is localized on chromosome 26, both bcntp97 and the h-type bcnt genes are found on bovine chromosome 18, a synteny region of human chromosome 16 on which human BCNT is localized. Complete nucleotide sequencing of the BAC clone reveals that the bcntp97 and h-type bcnt genes are located just 6 kb apart in a tandem manner. The two h-type bcnt and bcntp97genes are active at both the transcriptional level and the protein level. H-type bovine Bcnt is more like human BCNT than p97Bcnt, when compared at their N-terminal regions. However, phylogenetic analysis using the N-terminal region of the bcnt gene family revealed that the duplication of bovine genes occurred within the bovine lineage with significantly accelerated substitution in bcntp97. This acceleration was not ascribed definitely to positive selection. After duplication, one of the bovine bcnt genes recruited the endonuclease domain of an intronic RTE-1 repeat accompanied by the accelerated substitution at the 5'-ORF, resulting in creation of a novel type of Bcnt protein in bovine.|
edit: Here's an earlier paper on this protein:
Gene. 2001 May 2;268(1-2):59-66.
Gene organization of bovine BCNT that contains a portion corresponding to an endonuclease domain derived from an RTE-1 (Bov-B LINE), non-LTR retrotransposable element: duplication of an intramolecular repeat unit downstream of the truncated RTE-1.
Edited by theyeti on Sep. 01 2003,15:39