Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The standard membrane filtration method of the UK has been modified in order to improve its specificity for enumerating Escherichia coli in the subtropical waters of Hong Kong. This involves incorporating into the membrane lauryl sulphate (mLS) method either an in situ urease test (the mLS-UA method), or an in situ beta-glucuronidase test (the mLS-GUD method). The false-positive errors of the mLS-UA and mLS-GUD methods are low, ranging from 3-5%. A comparison between the membrane filtration (mLS-UA) method and the multiple tube technique in testing E. coli in subtropical beach-waters has demonstrated that the former can give much more precise counts, and is the method of choice for such a purpose. The mLS-GUD method, for which automated counting of E. coli colonies is possible, is a good alternative to mLS-UA in routine enumeration of this bacterial indicator in environmental waters.
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PMID:Methods for enumerating Escherichia coli in subtropical waters. 201 2

Nitrite reductase (NiR) is the second enzyme in the nitrate assimilatory pathway reducing nitrite to ammonium. The expression of the NiR gene is induced upon the addition of nitrate. In an earlier study, a 130 bp upstream region of the spinach NiR gene promoter, located between -330 to - 200, was shown to be necessary for nitrate induction of beta-glucuronidase (GUS) expression in tissue-specific manner in transgenic tobacco plant [28]. To further delineate the cis-acting elements involved in nitrate regulation of NiR gene expression, transgenic tobacco plants were generated with 5' deletions in the -330 to -200 region of the spinach NiR gene promoter fused to the GUS gene. Plants with the NiR promoter deleted to -230 showed a considerable increase in GUS activity in the presence of nitrate, indicating that the 30 bp region between -230 to -200 is crucial for nitrate-regulated expression of NiR. In vivo DMS footprinting of the -300 to -130 region of the NiR promoter in leaf tissues from two independent transgenic lines revealed several nitrate-inducible footprints. Footprinting within the -230 to -181 region revealed factor binding to two adjacent GATA elements separated by 24 bp. This arrangement of GATA elements is analogous to cis-regulatory sequences found in the promoters of nitrate-inducible genes of Neurospora crassa, regulated by the NIT2 Zn-finger protein. The -240 to -110 fragment of the NiR promoter, which contains two NIT2 consensus core elements, bound in vitro to a fusion protein comprising the zinc finger domain of the N. crassa NIT2 protein. The data presented here show that nitrate-inducible expression of the NiR gene is mediated by nitrate-specific binding of trans-acting factors to sequences preserved between fungi and higher plants.
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PMID:Footprinting of the spinach nitrite reductase gene promoter reveals the preservation of nitrate regulatory elements between fungi and higher plants. 922 57