2J9I

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.

Summary for 2J9I

• Entry DOI: 10.2210/pdb2j9i/pdb
• EMDB information: 1290
• Descriptor: GLUTAMATE-AMMONIA LIGASE DOMAIN-CONTAINING PROTEIN 1 (1 entity in total)
• Functional Keywords: ligase
• Biological source: MUS MUSCULUS (HOUSE MOUSE)
• Total number of polymer chains: 12
• Total formula weight: 475056.00

Authors

Wyatt, K.,White, H.E.,Wang, L.,Bateman, O.A.,Slingsby, C.,Orlova, E.V.,Wistow, G. (deposition date: 2006-11-09, release date: 2006-12-13, Last modification date: 2024-05-08)

Primary citation

Wyatt, K.,White, H.E.,Wang, L.,Bateman, O.A.,Slingsby, C.,Orlova, E.V.,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, 14:1823-, 2006

PubMed Abstract: 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.

PubMed: 17161372
DOI: 10.1016/J.STR.2006.10.008

Experimental method

ELECTRON MICROSCOPY (17 Å)