Biology:MOCS2

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Generic protein structure example

Molybdenum cofactor synthesis protein 2A and molybdenum cofactor synthesis protein 2B are a pair of proteins that in humans are encoded from the same MOCS2 gene.[1][2][3] These two proteins dimerize to form molybdopterin synthase.

Function

Eukaryotic molybdoenzymes use a unique molybdenum cofactor (MoCo) consisting of a pterin and the catalytically active metal molybdenum. MoCo is synthesized from cyclic pyranopterin monophosphate (precursor Z) by the heterodimeric enzyme molybdopterin synthase.[3]

Gene

The large and small subunits of molybdopterin synthase are both encoded from the MOCS2 gene by overlapping open reading frames. The proteins were initially thought to be encoded from a bicistronic transcript. They are now thought to be encoded from monocistronic transcripts. Alternatively spliced transcripts have been found for this locus that encode the large and small subunits.[3]

The MOCS2 gene contains 7 exons. Exons 1 to 3 encode MOCS2A (the small subunit), and exons 3 to 7 encode MOCS2B (large subunit).[1]

Genetic disease

Defects in both copies of MOCS2 cause the molybdenum cofactor deficiency disease in babies.[4]

Protein structure

MOCS2A and MOCS2B subunits form dimers in solution. These dimers in turn dimerize to form the tetrameric molybdopterin synthase complex.[5]

References

  1. 1.0 1.1 "Human molybdopterin synthase gene: genomic structure and mutations in molybdenum cofactor deficiency type B". American Journal of Human Genetics 64 (3): 706–11. March 1999. doi:10.1086/302296. PMID 10053004. 
  2. "The two subunits of human molybdopterin synthase: evidence for a bicistronic messenger RNA with overlapping reading frames". Nucleic Acids Research 27 (3): 854–8. February 1999. doi:10.1093/nar/27.3.854. PMID 9889283. 
  3. 3.0 3.1 3.2 EntrezGene 4338: MOCS2 molybdenum cofactor synthesis 2
  4. "A Turkish case with molybdenum cofactor deficiency". Nucleosides, Nucleotides & Nucleic Acids 25 (9–11): 1087–91. 2006. doi:10.1080/15257770600894022. PMID 17065069. 
  5. "Mechanistic studies of human molybdopterin synthase reaction and characterization of mutants identified in group B patients of molybdenum cofactor deficiency". The Journal of Biological Chemistry 278 (28): 26127–34. July 2003. doi:10.1074/jbc.M303092200. PMID 12732628. 

Further reading