Table 1. Attributes of CuMMO-containing organisms represented in culture.
| Systematic group | Selected examples | CuMMOsa | Other MOs | Commentsb |
|---|---|---|---|---|
| γ-Proteobacteria methanotrophs | Methylococcus capsulatus | PMMO (homoalleles) | sMMO | ‘Obligate' methylotroph, facultatively dependent on CuMMO |
| Methylobacter album | PMMO, pXMO (heteroalleles) | ‘Obligate' methylotroph, dependent on CuMMO. The CuMMO homolog pxmA is of unknown function | ||
| Candidatus Crenothrix polyspora | pMMO | Not in pure culture, data from enriched culture analysis | ||
| α-Proteobacteria methanotrophs | Ms. trichosporium (Methylocystaceae) | pMMO (heteroalleles) | sMMO | ‘Obligate' methylotroph, facultatively dependent on CuMMO |
| Methylocystis sp. SC2 (Methylocystaceae) | pMMO (heteroalleles) | ‘Obligate' methylotroph, dependent on CuMMO. CuMMO alleles differ in methane affinity | ||
| Methylocapsa acidiphila (Beijerinckiaceae) | pMMO | ‘Obligate' methylotroph, dependent on CuMMO | ||
| Methylocella silvestrisc (Beijerinckiaceae) | none | sMMO | Restricted facultative methylotroph, no CuMMO | |
| Verrucomicrobiales methanotrophs | Ma. Infernorum (Verrucomicrobiales) | pMMO (heteroalleles) | ‘Obligate' methylotroph, extreme acidophile. Both CuMMO alleles lack ligands for the binuclear copper center. At least one of the two CuMMOs is inferred to be a pMMO | |
| Candidate division NC10 Anaerobic methanotrophs | Candidatus Methylomirabilis oxyfera | pMMO | Not in pure culture, data from enriched culture analysis | |
| β-Proteobacteria AOB | Nitrosomonas europaea | AMO (homoalleles) | Lithoautotroph, dependent on CuMMO | |
| γ-Proteobacteria AOB | Nitrosococcus oceanus | AMO | Lithoautotroph, dependent on CuMMO | |
| Thaumarchaeota AOA | Nitrosopumilus maritima | AAMO | Lithoautotroph, dependent on CuMMOd | |
| Actinobacteria | Mycobacterium NBB4 | HMO | Eight | Heterotrophs with wide substrate range. |
| Small alkane | Mycobacterium NBB3 | PBMO | Two | Facultative CuMMO metabolisme |
| degraders | Nocardioides CF8 | HMO | ? |
Abbreviations: AOA, ammonia-oxidizing archaea; AOB, ammonia-oxidizing bacteria; CuMMO, copper membrane monooxygenase.
The number of copies and degree of relatedness of CuMMO alleles is complex and may vary within strains of a species. The term heteroalleles indicates copies proven, or thought, to encode functionally different enzymes exist.
The term ‘obligate' refers to practical laboratory growth on exogenously supplied substrates.
Included for comparative purposes—one of only two known methanotrophs that do not contain a CuMMO.
AAMO—Archaeal ammonia monooxygenase. Very divergent with distinct operon structure.
The propane degrader Mycobacterium JOB5 almost certainly contains a CuMMO. A CuMMO is present in the genome of the uncharacterized organism Nocardioides Broad-1 (gb:ADVI01000043).