title: Structural and biochemical study of Bacillus subtilis HmoB in complex with heme.
abstract: Most bacteria have developed a hemoprotein degradation system to acquire iron from their hosts. Bacillus subtilis HmoB, a heme monooxygenase, is involved in the degradation of heme and subsequent release of iron. HmoB contains a C-terminal ABM domain, which is similar in sequence and structure to other heme monooxygenases. Heme degradation assay showed that highly conserved residues (N70, W128, and H138) near the heme-binding site were critical for activity of HmoB. However, HmoB was shown to be different from other bacterial heme oxygenases due to its longer N-terminal region and formation of a biological monomer instead of a dimer. The degradation product of B. subtilis HmoB was identified as staphylobilin from mass spectrometric analysis of the product and release of formaldehyde during degradation reaction.
authors.affiliation: Ildong Pharmaceutical Co., Ltd, Gyeonggi-do 445-170, Republic of Korea.
authors.forename: Seonghun
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Life Science, University of Seoul, Seoul 130-743, Republic of Korea.
authors.forename: Dajeong
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Sogang University, Seoul 121-742, Republic of Korea.
authors.forename: Inae
authors.initials: I
authors.lastname: Jang
authors.affiliation: Department of Chemistry, Sogang University, Seoul 121-742, Republic of Korea.
authors.forename: Han Bin
authors.initials: HB
authors.lastname: Oh
authors.affiliation: Department of Life Science, University of Seoul, Seoul 130-743, Republic of Korea. Electronic address: jchoe@uos.ac.kr.
authors.forename: Jungwoo
authors.initials: J
authors.lastname: Choe
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D005798:Genes, Bacterial; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D006418:Heme; D006419:Heme Oxygenase (Decyclizing)
keywords: ABM domain; Crystallography; Heme degradation; Heme monooxygenase; Iron