6W6N
K106L/A131E mutant of cytochrome P460 from Nitrosomonas sp. AL212
Summary for 6W6N
| Entry DOI | 10.2210/pdb6w6n/pdb |
| Descriptor | Cytochrome P460, HEME C (3 entities in total) |
| Functional Keywords | cytochrome c, nh2oh oxidation, metal binding protein |
| Biological source | Nitrosomonas sp. AL212 |
| Total number of polymer chains | 2 |
| Total formula weight | 37049.04 |
| Authors | Coleman, R.E.,Lancaster, K.M. (deposition date: 2020-03-17, release date: 2020-06-24, Last modification date: 2024-10-16) |
| Primary citation | Coleman, R.E.,Vilbert, A.C.,Lancaster, K.M. The Heme-Lys Cross-Link in Cytochrome P460 Promotes Catalysis by Enforcing Secondary Coordination Sphere Architecture. Biochemistry, 59:2289-2298, 2020 Cited by PubMed Abstract: Cytochrome (cyt) P460 is a -type monoheme enzyme found in ammonia-oxidizing bacteria (AOB) and methanotrophs; additionally, genes encoding it have been found in some pathogenic bacteria. Cyt P460 is defined by a unique post-translational modification to the heme macrocycle, where a lysine (Lys) residue covalently attaches to the 13' carbon of the porphyrin, modifying this heme macrocycle into the enzyme's eponymous P460 cofactor, similar to the cofactor found in the enzyme hydroxylamine oxidoreductase. This cross-link imbues the protein with unique spectroscopic properties, the most obvious of which is the enzyme's green color in solution. Cyt P460 from the AOB is a homodimeric redox enzyme that produces nitrous oxide (NO) from 2 equiv of hydroxylamine. Mutation of the Lys cross-link results in spectroscopic features that are more similar to those of standard cyt ' proteins and renders the enzyme catalytically incompetent for NHOH oxidation. Recently, the necessity of a second-sphere glutamate (Glu) residue for redox catalysis was established; it plausibly serves as proton relay during the first oxidative half of the catalytic cycle. Herein, we report the first crystal structure of a cross-link deficient cyt P460. This structure shows that the positioning of the catalytically essential Glu changes by approximately 0.8 Å when compared to a cross-linked, catalytically competent cyt P460. It appears that the heme-Lys cross-link affects the relative position of the P460 cofactor with respect to the second-sphere Glu residue, therefore dictating the catalytic competency of the enzyme. PubMed: 32525655DOI: 10.1021/acs.biochem.0c00261 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.25 Å) |
Structure validation
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