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Paracoccus denitrificans possesses two BioR homologs having a role in regulation of biotin metabolism.

Feng Y, Kumar R, Ravcheev DA, Zhang H - Microbiologyopen (2015)

Bottom Line: The identity of the purified BioR proteins (BioR1 and BioR2) was confirmed with LC-QToF-MS.EMSA-based screening failed to demonstrate that the biotin-related metabolite is involved in BioR-DNA interplay, which is consistent with our former observation with Brucella BioR.Our finding defined a complex regulatory network for biotin metabolism in P. denitrificans by two BioR proteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Microbiology & Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.

No MeSH data available.


Related in: MedlinePlus

Alteration of bioexpression by addition of biotin. (A) Induction of the bioY-containing operon bioYB2 by addition of exogenous biotin. (B) Repression of the biotin biosynthesis operon bioBFDA in the presence of excess of biotin The inside cartoon diagram illustrates the genetic organization of bio operons. 100 nmol/L biotin was added into the Paracoccus denitrificans grown in minimal medium, and real-time quantitative PCR is used to measure the relative expression of biotin-related genes.
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fig08: Alteration of bioexpression by addition of biotin. (A) Induction of the bioY-containing operon bioYB2 by addition of exogenous biotin. (B) Repression of the biotin biosynthesis operon bioBFDA in the presence of excess of biotin The inside cartoon diagram illustrates the genetic organization of bio operons. 100 nmol/L biotin was added into the Paracoccus denitrificans grown in minimal medium, and real-time quantitative PCR is used to measure the relative expression of biotin-related genes.

Mentions: We carried out qPCR assays to investigate the response of P. denitrificans to biotin by addressing the accumulated transcript level of the representative target genes that correspond to the two biotin-acquiring systems (bioY is for biotin uptake system, and bioB, bioF, bioD, and bioA are specific for biotin synthesis pathway, Fig.8). First, we observed that an addition of exogenous biotin (100 nmol/L) to cultures of the wild-type strain PD1222 gave more than 10-fold increment to transcription of the bioYB2 operon, but did not alter significantly the expression of bioR1 (Fig.8A). Somewhat, it seemed usual in that the increasing expression of BioB, an enzyme catalyzing the last committed step of biotin synthesis is energetically wasteful on the condition with the supply of exogenous biotin. Someone might conclude that it is not physiologically correct that the bioB2 is co-transcribed with bioY forming an operon of bioYB2. In contrast, we favored to believe it is possible. The reasons being in the following two points: (1) Although all the intermediates can enter E. coli at various efficiencies, the biotin transporter BioY might be helpful for uptake of DTB, a precursor for biotin (also the substrate of BioB biotin synthase); (2) when the DTB is available, expression of functional BioB is physiologically required to make biotin from DTB. Given the fact that no literature documented the above speculation thus far, it would be of much interest to test it. This hypothesis might be checked by seeing if DTB competes with biotin in a bioB strain. The criteria for this assay is described as follows: If DTB uses the same transporter, then the minimal amount of biotin will not be enough (this idea is mainly from personal communication with Prof. John Cronan, University of Illinois at Urbana-Champaign, Urbana, IL).


Paracoccus denitrificans possesses two BioR homologs having a role in regulation of biotin metabolism.

Feng Y, Kumar R, Ravcheev DA, Zhang H - Microbiologyopen (2015)

Alteration of bioexpression by addition of biotin. (A) Induction of the bioY-containing operon bioYB2 by addition of exogenous biotin. (B) Repression of the biotin biosynthesis operon bioBFDA in the presence of excess of biotin The inside cartoon diagram illustrates the genetic organization of bio operons. 100 nmol/L biotin was added into the Paracoccus denitrificans grown in minimal medium, and real-time quantitative PCR is used to measure the relative expression of biotin-related genes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554459&req=5

fig08: Alteration of bioexpression by addition of biotin. (A) Induction of the bioY-containing operon bioYB2 by addition of exogenous biotin. (B) Repression of the biotin biosynthesis operon bioBFDA in the presence of excess of biotin The inside cartoon diagram illustrates the genetic organization of bio operons. 100 nmol/L biotin was added into the Paracoccus denitrificans grown in minimal medium, and real-time quantitative PCR is used to measure the relative expression of biotin-related genes.
Mentions: We carried out qPCR assays to investigate the response of P. denitrificans to biotin by addressing the accumulated transcript level of the representative target genes that correspond to the two biotin-acquiring systems (bioY is for biotin uptake system, and bioB, bioF, bioD, and bioA are specific for biotin synthesis pathway, Fig.8). First, we observed that an addition of exogenous biotin (100 nmol/L) to cultures of the wild-type strain PD1222 gave more than 10-fold increment to transcription of the bioYB2 operon, but did not alter significantly the expression of bioR1 (Fig.8A). Somewhat, it seemed usual in that the increasing expression of BioB, an enzyme catalyzing the last committed step of biotin synthesis is energetically wasteful on the condition with the supply of exogenous biotin. Someone might conclude that it is not physiologically correct that the bioB2 is co-transcribed with bioY forming an operon of bioYB2. In contrast, we favored to believe it is possible. The reasons being in the following two points: (1) Although all the intermediates can enter E. coli at various efficiencies, the biotin transporter BioY might be helpful for uptake of DTB, a precursor for biotin (also the substrate of BioB biotin synthase); (2) when the DTB is available, expression of functional BioB is physiologically required to make biotin from DTB. Given the fact that no literature documented the above speculation thus far, it would be of much interest to test it. This hypothesis might be checked by seeing if DTB competes with biotin in a bioB strain. The criteria for this assay is described as follows: If DTB uses the same transporter, then the minimal amount of biotin will not be enough (this idea is mainly from personal communication with Prof. John Cronan, University of Illinois at Urbana-Champaign, Urbana, IL).

Bottom Line: The identity of the purified BioR proteins (BioR1 and BioR2) was confirmed with LC-QToF-MS.EMSA-based screening failed to demonstrate that the biotin-related metabolite is involved in BioR-DNA interplay, which is consistent with our former observation with Brucella BioR.Our finding defined a complex regulatory network for biotin metabolism in P. denitrificans by two BioR proteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Microbiology & Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.

No MeSH data available.


Related in: MedlinePlus