Free Newsletter
Register for our Free Newsletters
Newsletter
Zones
Advanced Composites
LeftNav
Aerospace
LeftNav
Amorphous Metal Structures
LeftNav
Analysis and Simulation
LeftNav
Asbestos and Substitutes
LeftNav
Associations, Research Organisations and Universities
LeftNav
Automation Equipment
LeftNav
Automotive
LeftNav
Biomaterials
LeftNav
Building Materials
LeftNav
Bulk Handling and Storage
LeftNav
CFCs and Substitutes
LeftNav
Company
LeftNav
Components
LeftNav
Consultancy
LeftNav
View All
Other Carouselweb publications
Carousel Web
Defense File
New Materials
Pro Health Zone
Pro Manufacturing Zone
Pro Security Zone
Web Lec
Pro Engineering Zone
 
 
 
News

The hmuQ and hmuD genes from Bradyrhizobium japonicum encode heme-degrading enzymes

DTI Globalwatch : 17 October, 2006  (Technical Article)
Utilization of heme by bacteria as a nutritional iron source involves the transport of exogenous heme, followed by cleavage of the heme macrocycle to release iron. Bradyrhizobium japonicum can use heme as an iron source, but no heme-degrading oxygenase has been described.
Utilization of heme by bacteria as a nutritional iron source involves the transport of exogenous heme, followed by cleavage of the heme macrocycle to release iron. Bradyrhizobium japonicum can use heme as an iron source, but no heme-degrading oxygenase has been described. Here, bioinformatics analyses of the B. japonicum genome identified two paralogous genes renamed hmuQ (bll7075) and hmuD (bll7423) that encode proteins with weak similarity to the heme-degrading monooxygenase IsdG from Staphylococcus aureus. The hmuQ gene is clustered with known heme transport genes in the genome. Recombinant HmuQ bound heme with a Kd value of 0.8 M and showed spectral properties consistent with a heme oxygenase. In the presence of a reductant, HmuQ catalyzed the degradation of heme and the formation of biliverdin. The hmuQ and hmuD genes complemented a Corynebacterium ulcerans heme oxygenase mutant in trans for utilization of heme as the sole iron source for growth. Furthermore, homologs of hmuQ and hmuD were identified in many bacterial genera, and the recombinant homolog from Brucella melitensis bound heme and catalyzed its degradation. The findings show that hmuQ and hmuD encode heme oxygenases and indicate that the IsdG family of heme-degrading monooxygenases is not restricted to gram-positive pathogenic bacteria.
Bookmark and Share
 
Home I Editor's Blog I News by Zone I News by Date I News by Category I Special Reports I Directory I Events I Advertise I Submit Your News I About Us I Guides
 
   © 2012 NewMaterials.com
Netgains Logo