The <it>dppBCDF </it>gene cluster of <it>Haemophilus influenzae</it>: Role in heme utilization
<p>Abstract</p> <p>Background</p> <p><it>Haemophilus influenzae </it>requires a porphyrin source for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. This porphyrin requirement may be satisfied by either heme alone, or prot...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2009-08-01
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| Series: | BMC Research Notes |
| Online Access: | http://www.biomedcentral.com/1756-0500/2/166 |
| Summary: | <p>Abstract</p> <p>Background</p> <p><it>Haemophilus influenzae </it>requires a porphyrin source for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. This porphyrin requirement may be satisfied by either heme alone, or protoporphyrin IX in the presence of an iron source. One protein involved in heme acquisition by <it>H. influenzae </it>is the periplasmic heme binding protein HbpA. HbpA exhibits significant homology to the dipeptide and heme binding protein DppA of <it>Escherichia coli</it>. DppA is a component of the DppABCDF peptide-heme permease of <it>E. coli</it>. <it>H. influenzae </it>homologs of <it>dppBCDF </it>are located in the genome at a point distant from <it>hbpA</it>. The object of this study was to investigate the potential role of the <it>H. influenzae dppBCDF </it>locus in heme utilization.</p> <p>Findings</p> <p>An insertional mutation in <it>dppC </it>was constructed and the impact of the mutation on the utilization of both free heme and various proteinaceous heme sources as well as utilization of protoporphyrin IX was determined in growth curve studies. The <it>dppC </it>insertion mutant strain was significantly impacted in utilization of all tested heme sources and protoporphyin IX. Complementation of the <it>dppC </it>mutation with an intact <it>dppCBDF </it>gene cluster <it>in trans </it>corrected the growth defects seen in the <it>dppC </it>mutant strain.</p> <p>Conclusion</p> <p>The <it>dppCBDF </it>gene cluster constitutes part of the periplasmic heme-acquisition systems <it>of H. influenzae</it>.</p> |
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| ISSN: | 1756-0500 |