Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The first temperature-dependent proteins (expressed at 37 degrees C, but not 26 degrees C) to be identified in Yersinia pestis were antigens 3 (fraction 1), 4 (pH 6 antigen), and 5 (hereafter termed KatY). Antigens 3 and 4 are now established virulence factors, whereas little is known about KatY, except that it is encoded chromosomally, produced in abundance, possesses modest catalase activity, and is shared by Yersinia pseudotuberculosis, but not Yersinia enterocolitica. We report here an improved chromatographic method (DEAE-cellulose, calcium hydroxylapatite, and Sephadex G-150) that yields enzymatically active KatY (2,423 U/mg of protein). Corresponding mouse monoclonal antibody 1B70.1 detected plasminogen activator-mediated hydrolysis of KatY, and a polyclonal rabbit antiserum raised against outer membranes of Y. pestis was enriched for anti-KatY. A sequenced approximately 16-kb Y. pestis DNA insert of a positive pLG338 clone indicated that katY encodes an 81.4-kDa protein (pI 6.98) containing a leader sequence of 2.6 kDa; the deduced molecular mass and pI of processed KatY were 78.8 kDa and 6. 43, respectively. A minor truncated variant (predicted molecular mass of 53.6 kDa) was also expressed. KatY is similar (39 to 59% identity) to vegetative bacterial catalase-peroxidases (KatG in Escherichia coli) and is closely related to plasmid-encoded KatP of enterohemorrhagic E. coli O157:H7 (75% identity). katY encoded a putative Ca2+-binding site, and its promoter contained three homologues to the consensus recognition sequence of the pCD-encoded transcriptional activator LcrF. rbsA was located upstream of katY, and cybB, cybC, dmsABC, and araD were mapped downstream. These genes are not linked to katG or katP in E. coli.
 ...
PMID:Molecular characterization of KatY (antigen 5), a thermoregulated chromosomally encoded catalase-peroxidase of Yersinia pestis. 1032 12

Major insights into the regulation of chromatin organization have stemmed from biochemical studies using Gal4-VP16, a chimeric transcriptional activator in which the DNA binding domain of Gal4p is fused to the activation domain of viral protein VP16. Unexpectedly, given previous intensive efforts to understand how Gal4-VP16 functions in the context of chromatin, we have uncovered a new mode of chromatin reorganization that is dependent on Gal4-VP16. This reorganization is performed by an activity in a crude DEAE (CD) fraction from budding yeast which also supports ATP-dependent assembly of physiologically spaced nucleosome arrays. Biochemical analysis reveals that the activity tightly associates with chromatin and reorganizes nucleosome arrays by a mechanism which is insensitive to ATP depletion after nucleosome assembly. It generates a chromatin organization in which a nucleosome is stably positioned immediately adjacent to Gal4p binding sites in the template DNA. Individual deletion of genes previously implicated in chromatin assembly and remodeling, namely, the histone chaperones NAP1, ASF1, and CAC1 and the SNF2-like DEAD/H ATPases SNF2, ISW1, ISW2, CHD1, SWR1, YFR038w, and SPT20, does not significantly perturb reorganization. Therefore, Gal4-VP16-directed chromatin reorganization in yeast can occur by an ATP-independent mechanism that does not require SAGA, SWI/SNF, Isw1, or Isw2 chromatin remodeling complexes.
 ...
PMID:Gal4-VP16 directs ATP-independent chromatin reorganization in a yeast chromatin assembly system. 1576 86