Linked Life Data

21255303

Source:http://linkedlifedata.com/resource/pubmed/id/21255303

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-1-24
pubmed:abstractText
Cobalamin (vitamin B(12)) production in Bacillus megaterium has served as a model system for the systematic evaluation of single and multiple directed molecular and genetic optimization strategies. Plasmid and genome-based overexpression of genes involved in vitamin B(12) biosynthesis, including cbiX, sirA, modified hemA, the operons hemAXCDBL and cbiXJCDETLFGAcysG(A)cbiYbtuR, and the regulatory gene fnr, significantly increased cobalamin production. To reduce flux along the heme branch of the tetrapyrrole pathway, an antisense RNA strategy involving silencing of the hemZ gene encoding coproporphyrinogen III oxidase was successfully employed. Feedback inhibition of the initial enzyme of the tetrapyrrole biosynthesis, HemA, by heme was overcome by stabilized enzyme overproduction. Similarly, the removal of the B(12) riboswitch upstream of the cbiXJCDETLFGAcysG(A)cbiYbtuR operon and the recombinant production of three different vitamin B(12) binding proteins (glutamate mutase GlmS, ribonucleotide triphosphate reductase RtpR and methionine synthase MetH) partly abolished B(12)-dependent feedback inhibition. All these strategies increased cobalamin production in B. megaterium. Finally, combinations of these strategies enhanced the overall intracellular vitamin B(12) concentrations but also reduced the volumetric cellular amounts by placing the organism under metabolic stress.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1751-7915
pubmed:author
pubmed:copyrightInfo
© 2009 The Authors. Journal compilation © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.
pubmed:issnType
Electronic
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24-37
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Metabolic engineering of cobalamin (vitamin B12) production in Bacillus megaterium.
pubmed:affiliation
Protein Science Group, Department of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't