PMID:8757844

Citation	Jin, H, Ren, Z, Pozsgay, JM, Elkins, C, Whitby, PW, Morton, DJ and Stull, TL (1996) Cloning of a DNA fragment encoding a heme-repressible hemoglobin-binding outer membrane protein from Haemophilus influenzae. Infect. Immun. 64:3134-41
Abstract	Haemophilus influenzae is able to use hemoglobin as a sole source of heme, and heme-repressible hemoglobin binding to the cell surface has been demonstrated. Using an affinity purification methodology, a hemoglobin-binding protein of approximately 120 kDa was isolated from H. influenzae type b strain HI689 grown in heme-restricted but not in heme-replete conditions. The isolated protein was subjected to N-terminal amino acid sequencing, and the derived amino acid sequence was used to design corresponding oligonucleotides. The oligonucleotides were used to probe a Southern blot of EcoRI-digested HI689 genomic DNA. A hybridizing band of approximately 4.2 kb was successfully cloned into pUC19. Using a 1.9-kb internal BglII fragment of the 4.2-kb clone as a probe, hybridization was seen in both typeable and nontypeable H. influenzae but not in other bacterial species tested. Following partial nucleotide sequencing of the 4.2-kb insert, a putative open reading frame was subcloned into an expression vector. The host Escherichia coli strain in which the cloned fragment was expressed bound biotinylated human hemoglobin, whereas binding of hemoglobin was not detected in E. coli with the vector alone. In conclusion, we hypothesize that the DNA fragment encoding an approximately 120-kDa heme-repressible hemoglobin-binding protein mediates one step in the acquisition of hemoglobin by H. influenzae in vivo.
Links	PubMed PMC174198
Keywords	Amino Acid Sequence; Bacterial Outer Membrane Proteins/genetics; Bacterial Proteins; Base Sequence; Carrier Proteins/biosynthesis; Carrier Proteins/genetics; Cloning, Molecular; Cross Reactions; DNA, Bacterial; Escherichia coli/genetics; Gene Expression Regulation, Bacterial/drug effects; Haemophilus ducreyi; Haemophilus influenzae/genetics; Heme/pharmacology; Hemoglobins/metabolism; Humans; Molecular Sequence Data; Open Reading Frames; Recombinant Proteins/biosynthesis; Sequence Homology, Amino Acid; Species Specificity
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
HAEIF:HGPB		GO:0019867 : outer membrane	ECO:0000315:		C		Figure 1	complete CACAO 3457

References

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