Crystallization (Comment) | Organism |
---|---|
sitting drop vapor diffusion method, structural analysis of RoxA from Xanthomonas sp. strain 35Y at a resolution of 1.8 A | Xanthomonas sp. 35Y |
to 1.8 A resolution. The enzyme shows an unusually low degree of secondary structure. RoxA incorporates both oxygen atoms of its cosubstrate dioxygen into the rubber cleavage product 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al | Streptomyces sp. K30 |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
rubber latex + O2 | Xanthomonas sp. 35Y | the enzyme is excreted by Xanthomonas to functionalize and cleave the inert latex biopolymer poly(cis-1,4-isoprene) into the more soluble (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal units | (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Streptomyces sp. K30 | Q3L8N0 | - |
- |
Xanthomonas sp. 35Y | Q7X0P3 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
rubber latex + O2 | the enzyme is excreted by Xanthomonas to functionalize and cleave the inert latex biopolymer poly(cis-1,4-isoprene) into the more soluble (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal units | Xanthomonas sp. 35Y | (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal | - |
? | |
rubber latex + O2 | the enzyme incorporates both oxygen atoms of its cosubstrate dioxygen into the rubber cleavage product (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal. Activation and cleavage of O2 require binding of polyisoprene, and thus the substrate needs to use hydrophobic access channels to reach the deeply buried active site of RoxA. The location and nature of these channels support a processive mechanism of latex cleavage | Xanthomonas sp. 35Y | (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal | - |
? |
Synonyms | Comment | Organism |
---|---|---|
roxA | - |
Xanthomonas sp. 35Y |
rubber oxygenase A | - |
Xanthomonas sp. 35Y |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
heme | a diheme c-type cytochrome | Xanthomonas sp. 35Y |
General Information | Comment | Organism |
---|---|---|
metabolism | the enzyme is excreted by Xanthomonas to functionalize and cleave the inert latex biopolymer poly(cis-1,4-isoprene) into the more soluble (4Z,8Z)-4,8-dimethyl-12-oxotrideca-4,8-dienal units | Xanthomonas sp. 35Y |
physiological function | RoxA is isolated with O2 stably bound to the active site heme iron. Activation and cleavage of O2 require binding of polyisoprene, and the substrate needs to use hydrophobic access channels to reach the deeply buried active site of RoxA. Both residues H312 and Y462 are ideally positioned to form hydrogen bonds that arrest the substrate chain, so that the bond connecting the third and fourth monomer is in close proximity to the O2 ligand at heme 1. After oxidative cleavage, the resulting 2-oxo-4,8-dimethyl-trideca-4,8-diene-1-al product dissociates, and RoxA slides along the isoprene chain until the terminus is again arrested by hydrogen bonds | Streptomyces sp. K30 |