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NifD
The ''Nif regulon'' is a set of seven operons used to regulate nitrogen fixation in the coliform bacterium Klebsiella pneumoniae under anaerobic and microaerophilic conditions. It includes 17 nif genes, and is situated between the his and the Shi-A operon of the bacterium. The Nif Regulon The nif regulon comprises 7 operons: nifRLA, nifJ, nifHDK, nifEN, nifUSVM, nifWF, nifBQ. nifRLA operon: The tight expression regulation of the nitrogen fixation (nif) genes is mediated by the products of the nifRLA operon. NifA activates transcription of nif genes by the alternative form of RNA polymerase, s54-holoenzyme. NifL is a negative regulatory gene which inhibits the activation of other nif genes by nifA protein. NifR is a repressor binding site, between the promoter of the nifRLA operon and the nifL gene. No protein coded by nifR gene has been found. nifHDK operon: comprises three structural genes: nifK nifD and nifH. nifK encodes for B-subunit of Component 1 of nitrogena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nif Gene
The ''nif'' genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The primary enzyme encoded by the ''nif'' genes is the nitrogenase complex which is in charge of converting atmospheric nitrogen (N2) to other nitrogen forms such as ammonia which the organism can use for various purposes. Besides the nitrogenase enzyme, the ''nif'' genes also encode a number of regulatory proteins involved in nitrogen fixation. The ''nif'' genes are found in both free-living nitrogen-fixing bacteria and in symbiotic bacteria associated with various plants. The expression of the ''nif'' genes is induced as a response to low concentrations of fixed nitrogen and oxygen concentrations (the low oxygen concentrations are actively maintained in the root environment of host plants). The first Rhizobium genes for nitrogen fixation (nif) and for nodulation (nod) were cloned in the early 1980s by Gary Ruvkun and Sharon R. Long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NifA
NIFA may refer to: *National Intercollegiate Flying Association * Nuclear Institute for Food and Agriculture *National Institute of Food and Agriculture *National Islamic Front of Afghanistan National Islamic Front of Afghanistan (Mahaz-e Milli-ye Islami-ye Afghanistan, Mahaz-i Milli-yi Islami-yi Afghanistan) is a political party in Afghanistan. It has been led, since its founding, by members of a prominent Sufi family, the Gaila ... {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repressor
In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein. This blocking or reducing of expression is called repression. Function If an inducer, a molecule that initiates the gene expression, is present, then it can interact with the repressor protein and detach it from the operator. RNA polymerase then can transcribe the message (expressing the gene). A co-repressor is a molecule that can bind to the repressor and make it bind to the operator tightly, which decreases transcription. A repressor that binds with a co-repressor is termed an ''aporepressor'' or ''inactive repressor''. One type of aporepressor is the trp repre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
