scholarly journals Specific binding of the regulatory protein ExpG to promoter regions of the galactoglucan biosynthesis gene cluster of Sinorhizobium meliloti - a combined molecular biology and force spectroscopy investigation

2003 ◽  
Vol 143 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Frank Wilco Bartels ◽  
Birgit Baumgarth ◽  
Dario Anselmetti ◽  
Robert Ros ◽  
Anke Becker
Keyword(s):  
Molecular Biology ◽  
Gene Cluster ◽  
Sinorhizobium Meliloti ◽  
Specific Binding ◽  
Regulatory Protein ◽  
Force Spectroscopy ◽  
Promoter Regions ◽  
Biosynthesis Gene Cluster ◽  
Biosynthesis Gene

Fur from Microcystis aeruginosa binds in vitro promoter regions of the microcystin biosynthesis gene cluster

2006 ◽  
Vol 67 (9) ◽  
pp. 876-881 ◽  
Author(s):  
Beatriz Martin-Luna ◽  
Emma Sevilla ◽  
José A. Hernandez ◽  
M. Teresa Bes ◽  
Maria F. Fillat ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Microcystis Aeruginosa ◽  
Promoter Regions ◽  
Biosynthesis Gene Cluster ◽  
Biosynthesis Gene

scholarly journals AraC-like transcriptional activator CuxR binds c-di-GMP by a PilZ-like mechanism to regulate extracellular polysaccharide production

2017 ◽  
Vol 114 (24) ◽  
pp. E4822-E4831 ◽  
Author(s):  
Simon Schäper ◽  
Wieland Steinchen ◽  
Elizaveta Krol ◽  
Florian Altegoer ◽  
Dorota Skotnicka ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Evolution ◽  
Dna Binding ◽  
Gene Cluster ◽  
Sinorhizobium Meliloti ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Biosynthesis Gene Cluster ◽  
Biosynthesis Gene ◽  
Helical Hairpin

Cyclic dimeric GMP (c-di-GMP) has emerged as a key regulatory player in the transition between planktonic and sedentary biofilm-associated bacterial lifestyles. It controls a multitude of processes including production of extracellular polysaccharides (EPSs). The PilZ domain, consisting of an N-terminal “RxxxR” motif and a β-barrel domain, represents a prototype c-di-GMP receptor. We identified a class of c-di-GMP–responsive proteins, represented by the AraC-like transcription factor CuxR in plant symbiotic α-proteobacteria. In Sinorhizobium meliloti, CuxR stimulates transcription of an EPS biosynthesis gene cluster at elevated c-di-GMP levels. CuxR consists of a Cupin domain, a helical hairpin, and bipartite helix-turn-helix motif. Although unrelated in sequence, the mode of c-di-GMP binding to CuxR is highly reminiscent to that of PilZ domains. c-di-GMP interacts with a conserved N-terminal RxxxR motif and the Cupin domain, thereby promoting CuxR dimerization and DNA binding. We unravel structure and mechanism of a previously unrecognized c-di-GMP–responsive transcription factor and provide insights into the molecular evolution of c-di-GMP binding to proteins.

scholarly journals Detailed studies of the binding mechanism of the Sinorhizobium meliloti transcriptional activator ExpG to DNA

Microbiology ◽  
2005 ◽  
Vol 151 (1) ◽  
pp. 259-268 ◽  
Author(s):  
Birgit Baumgarth ◽  
Frank Wilco Bartels ◽  
Dario Anselmetti ◽  
Anke Becker ◽  
Robert Ros
Keyword(s):  
Binding Site ◽  
Single Molecule ◽  
Sinorhizobium Meliloti ◽  
Specific Binding ◽  
Dna Interaction ◽  
Dynamic Force ◽  
Sequence Motifs ◽  
Promoter Regions ◽  
Dissociation Kinetics ◽  
Direct Binding

The exopolysaccharide galactoglucan promotes the establishment of symbiosis between the nitrogen-fixing Gram-negative soil bacterium Sinorhizobium meliloti 2011 and its host plant alfalfa. The transcriptional regulator ExpG activates expression of galactoglucan biosynthesis genes by direct binding to the expA1, expG/expD1 and expE1 promoter regions. ExpG is a member of the MarR family of regulatory proteins. Analysis of target sequences of an ExpG(His)6 fusion protein in the exp promoter regions resulted in the identification of a binding site composed of a conserved palindromic region and two associated sequence motifs. Association and dissociation kinetics of the specific binding of ExpG(His)6 to this binding site were characterized by standard biochemical methods and by single-molecule spectroscopy based on the atomic force microscope (AFM). Dynamic force spectroscopy indicated a distinct difference in the kinetics between the wild-type binding sequence and two mutated binding sites, leading to a closer understanding of the ExpG–DNA interaction.

scholarly journals Characterization of the Biosynthesis Gene Cluster for the Pyrrole Polyether Antibiotic Calcimycin (A23187) inStreptomyces chartreusisNRRL 3882

2010 ◽  
Vol 55 (3) ◽  
pp. 974-982 ◽  
Author(s):  
Qiulin Wu ◽  
Jingdan Liang ◽  
Shuangjun Lin ◽  
Xiufen Zhou ◽  
Linquan Bai ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Mutational Analysis ◽  
Divalent Cations ◽  
Biological Effects ◽  
Biosynthetic Gene Cluster ◽  
Type I ◽  
Biosynthesis Gene Cluster ◽  
Biosynthesis Gene ◽  
Hydroxyanthranilic Acid

ABSTRACTThe pyrrole polyether antibiotic calcimycin (A23187) is a rare ionophore that is specific for divalent cations. It is widely used as a biochemical and pharmacological tool because of its multiple, unique biological effects. Here we report on the cloning, sequencing, and mutational analysis of the 64-kb biosynthetic gene cluster fromStreptomyces chartreusisNRRL 3882. Gene replacements confirmed the identity of the gene cluster, andin silicoanalysis of the DNA sequence revealed 27 potential genes, including 3 genes for the biosynthesis of the α-ketopyrrole moiety, 5 genes that encode modular type I polyketide synthases for the biosynthesis of the spiroketal ring, 4 genes for the biosynthesis of 3-hydroxyanthranilic acid, anN-methyltransferase tailoring gene, a resistance gene, a type II thioesterase gene, 3 regulatory genes, 4 genes with other functions, and 5 genes of unknown function. We propose a pathway for the biosynthesis of calcimycin and assign the genes to the biosynthesis steps. Our findings set the stage for producing much desired calcimycin derivatives using genetic modification instead of chemical synthesis.

scholarly journals Enhancement of the Diversity of Polyoxins by a Thymine-7-Hydroxylase Homolog outside the Polyoxin Biosynthesis Gene Cluster

2010 ◽  
Vol 76 (21) ◽  
pp. 7343-7347 ◽  
Author(s):  
Changming Zhao ◽  
Tingting Huang ◽  
Wenqing Chen ◽  
Zixin Deng
Keyword(s):  
Gene Cluster ◽  
Carbon Skeleton ◽  
Open Reading Frame ◽  
Streptomyces Avermitilis ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
Biosynthesis Gene ◽  
Pyrimidine Moiety

ABSTRACT Polyoxins consist of 14 structurally variable components which differentiate at three branch sites of the carbon skeleton. Open reading frame (ORF) SAV_4805 of Streptomyces avermitilis, showing similarity to thymine-7-hydroxylase, was proved to enhance the diversity of polyoxins at the C-5 site of the 1-(5′-amino-5′-deoxy-β-d-allofuranuronosyl) pyrimidine moiety.

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