Vitamin A-post translational modification

[sameeralord]

The question is give an example of post translational modifcation of a protei brought about my vitamin A. Now I checked my book which says vitamin A plays a role in vision, reproduction, growth, maintenance of epithelial cells. I checked the net as well couldn't find the answer . Can anyone tell me the name, so I can search info about it, some info would also be good if possible. Thanks

 

[Ygggdrasil]

Read up on the role of vitamin A in vision. A very important protein in vision binds covalently to a derivative of vitamin A.

 

[sameeralord]

Read up on the role of vitamin A in vision. A very important protein in vision binds covalently to a derivative of vitamin A.

Thanks Yggg , ok I checked and it seems opsin binds with 11-cis retinal. Now upto this point I thought post translational modification mean hydoxylation,carboxylation etc. Is adding coenzymes also an example? wait this is not adding a coenzyme right, rhodposin is going to dissociate again. I don't understand why this is an example of post translational modification.

 

[Ygggdrasil]

I would classify any chemical modification to a protein after it has been synthesized by the ribosome as a post-translational modification. Since retinal covalently binds to a lysine of opsin, this would seem to fit that definition. So would covalent binding of other co-factors like heme groups.

 

[sameeralord]

I would classify any chemical modification to a protein after it has been synthesized by the ribosome as a post-translational modification. Since retinal covalently binds to a lysine of opsin, this would seem to fit that definition. So would covalent binding of other co-factors like heme groups.

Thanks