title: Comparative analysis of hmuO function and expression in Corynebacterium species.
abstract: We have constructed defined deletions in the hmuO gene from Corynebacterium diphtheriae and Corynebacterium ulcerans and show that the C. ulcerans hmuO mutation results in a significant reduction in hemoglobin-iron utilization, whereas in C. diphtheriae strains, deletion of hmuO caused no or only partial reduction in the utilization of heme as an iron source. We also show that expression from the C. ulcerans hmuO promoter exhibits minimal regulation by iron and heme whereas transcription from the C. diphtheriae hmuO promoter shows both significant iron repression and heme-dependent activation. These findings indicate that variability in HmuO function and expression exists among Corynebacterium species.
authors.affiliation: Laboratory of Respiratory and Special Pathogens, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Adminisstration, Bethesda, MD 20892, USA.
authors.forename: Carey A
authors.initials: CA
authors.lastname: Kunkle
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schmitt
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D003352:Corynebacterium / Q000235:genetics / Q000502:physiology*; D003353:Corynebacterium diphtheriae / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D006418:Heme / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D007501:Iron / Q000378:metabolism*; D008969:Molecular Sequence Data; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D006418:Heme; D007501:Iron; D006419:Heme Oxygenase (Decyclizing); C104107:HmuO protein, bacteria