VXN

VXN is found along the plus strand of chromosome 8.[6] The entire gene is 58,522 bp long.[6] VXN is flanked by alcohol dehydrogenase iron containing 1 and Myb proto-oncogene like 1.[5]

Gene neighborhood of VXN along the forward strand of chromosome 8.

No human paralogs for VXN have been identified[5]

Phylogentic tree of select orthologs of the gene VXN. Estimated date of divergence is shown.

Vexin is found in all classes of vertebrates, including mammals, birds, fish, reptiles and amphibians.[5] The most distant ortholog of VXN is in Callorhinchus milli, which diverged from the human version of the gene an estimated 482.9 million years ago.[7] The gene has not been found in any plants, fungi or single celled organisms.[5]

The N-terminus and C-terminus are highly conserved regions across both distant and close orthologs. The orthologs of vexin all show conservation of the SH3 protein domain family as well as a domain of unknown function (DUF4648).

VXN does not have any alternative mRNA splice variants. The mature mRNA is approximately 3,741 base pairs in length and contains six exons.[6]

Location of the domain of unknown function and nuclear localization signal along vexin.

Vexin is 207 amino acids long, which equates to a molecular weight of 22.6 kdal.[6] The isoelectric point of the protein is 10.42 which indicates the pH of the protein is basic.[8] Vexin does contain a domain of unknown function (DUF4648) and is a part of the SH3 domain family, which is known to bind to proline-rich ligands.[5] The secondary and tertiary structure of this protein is not well known.

Vexin is considered rich in arginine, and poor in phenylalanine compared to the composition of the average human protein.[8] Vexin does contain several regions of positively charged runs and has a high concentration of basic amino acids.[8]

Vexin is predicted to undergo several types of post translational modifications. With a high degree of certainty, it is predicted that vexin undergoes lysine glycation, O-glycosylation, serine, threonine and tyrosine phosphorylation, SUMOylation and initial methionine acetylation.[9]

Conceptual translation of VXN depicts predicted post-translational modification sites.

Vexin is predicted to be a nuclear protein, given the classical nuclear localization signal found at amino acids Lys191 to Lys193.[9] Vexin does not contain any transmembrane domains or signal peptides suggesting that it is an intracellular protein.[9]