CRYM
Description
The CRYM (crystallin mu) is a protein-coding gene located on chromosome 16.
CRYM, also known as NADP-regulated thyroid-hormone-binding protein (THBP), is a protein encoded by the CRYM gene in humans. Multiple alternatively spliced transcript variants have been found for this gene. Crystallins are divided into two classes: taxon-specific and ubiquitous. Taxon-specific crystallins are also known as phylogenetically-restricted crystallins. Ubiquitous crystallins are the major proteins of vertebrate eye lens and maintain its transparency and refractive index. CRYM encodes a taxon-specific crystallin protein that binds NADPH and has sequence similarity to bacterial ornithine cyclodeaminases. The protein does not play a structural role in lens tissue; instead, it binds thyroid hormone for possible regulatory or developmental functions. CRYM's enzymatic function has been identified as a ketimine reductase, reducing cyclic ketimines to their reduced forms. It can utilize either NADH or NADPH as a cofactor. At pH 5.0, the most active substrate is aminoethylcysteine ketimine (AECK), while at neutral pH (7.2), the most active substrate is 1-piperideine-2-carboxylate, which is important in the pipecolic acid pathway.
CRYM is also known as DFNA40, THBP.
