title: Identification of a haem-utilization protein (Hup) in Haemophilus influenzae.
abstract: Haemophilus influenzae has an absolute growth requirement for a porphyrin source. This growth requirement can be satisfied in vitro by haem, haemoglobin or the haemoglobin-haptoglobin, haem-haemopexin and haem-albumin complexes. A family of proteins, termed the Hgp proteins, which are essential for utilization of the haemoglobin-haptoglobin complex, has previously been identified. A strain lacking the Hgp proteins also has a residual ability to utilize haemoglobin, indicating that additional moieties contribute to haemoglobin utilization. Using a haemoglobin affinity method an approximately 105 kDa protein was isolated. Mutation of the identified gene in an Hgp null background reduced the ability of the mutant strain to utilize haemoglobin in vitro. The mutation also resulted in a reduced ability to utilize haem, haem-haemopexin, haem-albumin and haemoglobin-haptoglobin, thus identifying a general haem-utilization protein (Hup) in Haemophilus influenzae.
authors.affiliation: Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Morton
authors.forename: Ann
authors.initials: A
authors.lastname: Smith
authors.forename: Zhen
authors.initials: Z
authors.lastname: Ren
authors.forename: Larissa L
authors.initials: LL
authors.lastname: Madore
authors.forename: Timothy M
authors.initials: TM
authors.lastname: VanWagoner
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Seale
authors.forename: Paul W
authors.initials: PW
authors.lastname: Whitby
authors.forename: Terrence L
authors.initials: TL
authors.lastname: Stull
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D016470:Bacteremia / Q000382:microbiology / Q000503:physiopathology; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins; D005260:Female; D006193:Haemophilus influenzae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006242:Haptoglobins / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006466:Hemopexin / Q000378:metabolism; D006801:Humans; D008583:Meningitis, Haemophilus / Q000382:microbiology / Q000503:physiopathology; D008969:Molecular Sequence Data; D009154:Mutation; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D017422:Sequence Analysis, DNA
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D006242:Haptoglobins; D006454:Hemoglobins; C497116:Hup, Haemophilus influenzae; C035492:haptoglobin-hemoglobin complex; D006418:Heme; D006466:Hemopexin