Carbon disulfide hydrolase
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| Carbon disulfide hydrolase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 3.13.1.5 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
| Identifiers | |
|---|---|
| Symbol | ? |
| SCOP2 | 1can / SCOPe / SUPFAM |
Carbon disulfide hydrolase is an enzyme that catalyzes carbon disulfide hydrolysis. It is hexadecameric, weighing 23,576 Da (per molecule).[1]
Carbon disulfide occurs naturally in the mudpots of volcanic solfataras. It is a precursor to hydrogen sulfide, which is an electron donor. The hyperthermophilic Acidianus strain was found to convert CS2 into H2S and CO2.[1]
The enzyme is similar to that of carbonic anhydrases. The enzyme monomer of CS2 hydrolase displays a typical β-carbonic anhydrase fold and active site. Two of these monomers form a closely intertwined dimer with a central β-sheet capped by an α-helical domain. Four dimers form a square octameric ring through interactions of the long arms at the N and C termini. Similar ring structures have been seen in strains of carbonic anhydrases, however, in CS2 hydrolase is an enzyme consisting of two octameric rings form a hexadecamer by interlocking at right angles to each other. This results in the blocking of the entrance to the active site and the formation of a single 15-Å-long, highly hydrophobic tunnel that functions as a specificity filter. This provides a key difference between carbonic anhydrase and CS2 hydrolase. This tunnel determines the enzyme's substrate specificity for CS2, which is hydrophobic as well.