Purification, crystallization and preliminary X-ray analysis of two hydrogen sulfide-producing enzymes from Fusobacterium nucleatum

Hydrogen sulfide produced by oral bacteria is responsible for oral malodour. Two homologous hydrogen sulfide-producing enzymes, Fn1220 and Cdl, from Fusobacterium nucleatum (which actively produces hydrogen sulfide) were overproduced, purified and crystallized. X-ray diffraction data were collected from the crystals using a synchrotron-radiation source. The Fn1220 crystal belonged to tetragonal space group P4₁2₁2 or P4₃2₁2 (unit-cell parameters a = b = 116.8, c = 99.2 Å) and the Cdl crystal belonged to monoclinic space group P2₁ (unit-cell parameters a = 84.9, b = 70.9, c = 87.6 Å, β = 90.3°).