Lengsin is a survivor of an ancient family of class I glutamine synthetases in eukaryotes that has undergone evolutionary re- engineering for a tissue-specific role in the vertebrate eye lens.
2j9i is a 12 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Checkto colour the structure by Evolutionary Conservation, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
Lengsin is a survivor of an ancient family of class I glutamine synthetases re-engineered by evolution for a role in the vertebrate lens.,Wyatt K, White HE, Wang L, Bateman OA, Slingsby C, Orlova EV, Wistow G Structure. 2006 Dec;14(12):1823-34. PMID:17161372[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Wyatt K, White HE, Wang L, Bateman OA, Slingsby C, Orlova EV, Wistow G. 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. 2006 Dec;14(12):1823-34. PMID:17161372 doi:http://dx.doi.org/10.1016/j.str.2006.10.008
