title: Isolation of flavohemoglobin from the actinomycete Streptomyces antibioticus grown without external nitric oxide stress.
abstract: A flavocytochrome protein was isolated from the actinomycete Streptomyces antibioticus. The purified protein contained protoheme and FAD, and its M(r) was estimated to be 52000. The absorption spectra in its resting oxidized, dithionite-reduced, carbon monoxide-bound, and oxygenated (O(2)-bound) forms were characteristic of those of flavohemoglobin (Fhb). The N-terminal amino acid sequence showed high identities to those of other Fhb's. Furthermore, the actinomycete flavocytochrome scavenged nitric oxide in the presence of NADH. These results demonstrated that the flavocytochrome is the first Fhb purified from actinomycetes. The actinomycete Fhb was produced in S. antibioticus cells in large amounts without any external nitric oxide (NO) stress, which is indicative of a physiological function of Fhb other than detoxification of NO.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Takaya
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Shoun
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D005420:Flavoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry; D006420:Hemeproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000737:chemistry; D018384:Oxidative Stress / Q000502:physiology*; D016415:Sequence Alignment; D013303:Streptomyces antibioticus / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005420:Flavoproteins; D016166:Free Radical Scavengers; D006420:Hemeproteins; D006454:Hemoglobins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase