title: Cloning and characterization of the L-cysteine desulfhydrase gene of Fusobacterium nucleatum.
abstract: Hydrogen sulfide and methyl mercaptan are the two major compounds associated with oral malodor. These compounds are highly toxic, and are thought to play an important role in periodontal disease. Fusobacterium nucleatum, an oral bacterium, produces large amounts of hydrogen sulfide from L-cysteine by the enzymatic action of L-cysteine desulfhydrase. We cloned and sequenced the cdl gene encoding L-cysteine desulfhydrase from F. nucleatum ATCC 10953, and revealed that the structural cdl gene consists of 921 bp and encodes a 33.4-kDa protein. The cloned gene was inserted into an expression vector, pDEST17, and expressed in Escherichia coli as a fused protein. The purified enzyme was tested for substrate specificity using various SH-containing compounds. Only L-cysteine served as a substrate for L-cysteine desulfhydrase to produce hydrogen sulfide.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Fukamachi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakano
authors.forename: Mamiko
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Koga
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003542:Cystathionine gamma-Lyase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D016967:Fusobacterium nucleatum / Q000201:enzymology* / Q000235:genetics*; D006209:Halitosis / Q000382:microbiology; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism; D008969:Molecular Sequence Data; D010510:Periodontal Diseases / Q000382:microbiology
chemical_list: D003542:Cystathionine gamma-Lyase; D006862:Hydrogen Sulfide