Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carotenoid synthesis in Escherichia coli, when transformed with plasmid containing a carotenoid gene cluster from Erwinia herbicola (pPL376), is regulated by RpoS. When the plasmid was transformed into E. coli mutants that were oxyR minus, the intracellular carotenoid concentration dramatically increased from that observed in an oxyR plus allele. The higher carotenoid concentration in these mutants correlated with an increase in rpoS transcription as indicated by beta-galactosidase activity from a rpoS::lacZ promoter fusion. This indication of a higher concentration of carotenoids correlated with an increased resistance to hydrogen peroxide and near-ultraviolet radiation (310-400 nm; near-UV).
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PMID:RpoS dependent overexpression of carotenoids from Erwinia herbicola in OXYR deficient Escherichia coli. 934 15

Astaxanthin, a high-value ketocarotenoid is mainly used in fish aquaculture. It also has potential in human health due to its higher antioxidant capacity than beta-carotene and vitamin E. The unicellular green alga Haematococcus pluvialis is known to accumulate astaxanthin in response to environmental stresses, such as high light intensity and salt stress. Carotenoid hydroxylase plays a key role in astaxanthin biosynthesis in H. pluvialis. In this paper, we report the characterization of a promoter-like region (-378 to -22 bp) of carotenoid hydroxylase gene by cloning, sequence analysis and functional verification of its 919 bp 5'-flanking region in H. pluvialis. The 5'-flanking region was characterized using micro-particle bombardment method and transient expression of LacZ reporter gene. Results of sequence analysis showed that the 5'-flanking region might have putative cis-acting elements, such as ABA (abscisic acid)-responsive element (ABRE), C-repeat/dehydration responsive element (C-repeat/DRE), ethylene-responsive element (ERE), heat-shock element (HSE), wound-responsive element (WUN-motif), gibberellin-responsive element (P-box), MYB-binding site (MBS) etc., except for typical TATA and CCAAT boxes. Results of 5' deletions construct and beta-galactosidase assays revealed that a highest promoter-like region might exist from -378 to -22 bp and some negative regulatory elements might lie in the region from -919 to -378 bp. Results of site-directed mutagenesis of a putative C-repeat/DRE and an ABRE-like motif in the promoter-like region (-378 to -22 bp) indicated that the putative C-repeat/DRE and ABRE-like motif might be important for expression of carotenoid hydroxylase gene.
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PMID:Characterization of carotenoid hydroxylase gene promoter in Haematococcus pluvialis. 1713 34