Molybdenum cofactor synthesis protein 2A and molybdenum cofactor synthesis protein 2B are a pair of

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

s that in humans are encoded from the same ''MOCS2''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

.: MOCS2 molybdenum cofactor synthesis 2 These two proteins dimerize to form

molybdopterin synthase Molybdopterin synthase (, MPT synthase) is an enzyme required to synthesize molybdopterin (MPT) from precursor Z (now known as cyclic pyranopterin monophosphate). Molydopterin is subsequently complexed with molybdenum to form molybdenum cofactor ( ...

Function

Eukaryotic

molybdoenzyme Molybdenum is an essential element in most organisms. It is most notably present in nitrogenase which is an essential part of nitrogen fixation Mo-containing enzymes Molybdenum is an essential element in most organisms; a 2008 research paper sp ...

s use a unique

molybdenum cofactor A molybdenum cofactor is a biochemical cofactor that contains molybdenum. Examples include: * Molybdopterin (or, strictly speaking, the molybdopterin-molybdenum-complex), the organophosphate-dithiolate ligand that binds molybdenum and tungsten ...

(MoCo) consisting of a

pterin Pterin is a heterocyclic compound composed of a pteridine ring system, with a "keto group" (a lactam) and an amino group on positions 4 and 2 respectively. It is structurally related to the parent bicyclic heterocycle called pteridine. Pterins, a ...

and the catalytically active metal

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lea ...

. MoCo is synthesized from

cyclic pyranopterin monophosphate Fosdenopterin (or cyclic pyranopterin monophosphate, cPMP), sold under the brand name Nulibry, is a medication used to reduce the risk of death due to a rare genetic disease known as molybdenum cofactor deficiency type A. The most common side ...

(precursor Z) by the

heterodimeric In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...

enzyme

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

Genetic disease

Defects in both copies of MOCS2 cause the

molybdenum cofactor deficiency Molybdenum cofactor deficiency is a rare human disease in which the absence of molybdopterin – and consequently its molybdenum complex, commonly called molybdenum cofactor – leads to accumulation of toxic levels of sulphite and neurological da ...

disease in babies.

Protein structure

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

Function

Gene

Genetic disease

Protein structure

References

Further reading