| First Author | Wyatt K | Year | 2006 |
| Journal | Structure | Volume | 14 |
| Issue | 12 | Pages | 1823-34 |
| PubMed ID | 17161372 | Mgi Jnum | J:206926 |
| Mgi Id | MGI:5553341 | Doi | 10.1016/j.str.2006.10.008 |
| Citation | Wyatt K, et al. (2006) Lengsin is a survivor of an ancient family of class I glutamine synthetases re-engineered by evolution for a role in the vertebrate lens. Structure 14(12):1823-34 |
| abstractText | Lengsin is a major protein of the vertebrate eye lens. It belongs to the hitherto purely prokaryotic GS I branch of the glutamine synthetase (GS) superfamily, but has no enzyme activity. Like the taxon-specific crystallins, Lengsin is the result of the recruitment of an ancient enzyme to a noncatalytic role in the vertebrate lens. Cryo-EM and modeling studies of Lengsin show a dodecamer structure with important similarities and differences with prokaryotic GS I structures. GS homology regions of Lengsin are well conserved, but the N-terminal domain shows evidence of dynamic evolutionary changes. Compared with birds and fish, most mammals have an additional exon corresponding to part of the N-terminal domain; however, in human, this is a nonfunctional pseudoexon. Genes related to Lengsin are also present in the sea urchin, suggesting that this branch of the GS I family, supplanted by GS II enzymes in vertebrates, has an ancient role in metazoans. |
