Fig. 1
From: Characterization of a long overlooked copper protein from methane- and ammonia-oxidizing bacteria
PmoDMet49242_1452 forms a dimeric species containing a CuA site. a Connections between pmo/amo, pmoD/amoD, amoE, copCD, and pCuAC genes in a range of AOB and MOB species. b Optical spectra of wild-type PmoDMet49242_1452 periplasmic domain (WT) and variants thereof (200 μM protein). All samples were loaded with ~2 equivalents copper and desalted prior to data collection. c SEC-MALS profiles for the two species isolated by size exclusion chromatography. Inset shows optical spectra collected at the apex of the predominant peak. Pink traces indicate the CuA species (molar mass 30,540 Da ± 2%) and gray traces indicate the monomeric species (molar mass 16,250 Da ± 3%). d CW X-band EPR spectra of CuA PmoDMet49242_1452; gx = 2.01, gy = 2.05, gz = 2.13. Brackets define the Cu hyperfine splitting at gz (Az). Conditions: 9.364 GHz microwave frequency, 16 G modulation amplitude, 160 ms time constant, 90 s per scan, temperature 20 K. e Cu XANES spectra for wild-type (solid line) and C65S (dashed line) PmoDMet49242_1452. Inset shows the first derivatives of both XANES spectra identifying features at 8983.2 and 8987.8 eV (first inflection energies at 8982.5 and 8985.3 eV) typical for mixed valent Cu(+1.5)–Cu(+1.5) species
