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)

Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of beta-1,4-glucan (cellulose) synthase in Acetobacter xylinum. The enzymes controlling turnover of c-di-GMP are diguanylate cyclase (DGC), which catalyzes its formation, and phosphodiesterase A (PDEA), which catalyzes its degradation. Following biochemical purification of DGC and PDEA, genes encoding isoforms of these enzymes have been isolated and found to be located on three distinct yet highly homologous operons for cyclic diguanylate, cdg1, cdg2, and cdg3. Within each cdg operon, a pdeA gene lies upstream of a dgc gene. cdg1 contains two additional flanking genes, cdg1a and cdg1d. cdg1a encodes a putative transcriptional activator, similar to AadR of Rhodopseudomonas palustris and FixK proteins of rhizobia. The deduced DGC and PDEA proteins have an identical motif structure of two lengthy domains in their C-terminal regions. These domains are also present in numerous bacterial proteins of undefined function. The N termini of the DGC and PDEA deduced proteins contain putative oxygen-sensing domains, based on similarity to domains on bacterial NifL and FixL proteins, respectively. Genetic disruption analyses demonstrated a physiological hierarchy among the cdg operons, such that cdg1 contributes 80% of cellular DGC and PDEA activities and cdg2 and cdg3 contribute 15 and 5%, respectively. Disruption of dgc genes markedly reduced in vivo cellulose production, demonstrating that c-di-GMP controls this process.
 ...
PMID:Three cdg operons control cellular turnover of cyclic di-GMP in Acetobacter xylinum: genetic organization and occurrence of conserved domains in isoenzymes. 972 Dec 78

A novel gene, eglC, encoding an endoglucanase, was cloned from Aspergillus niger. Transcription of eglC is regulated by XlnR, a transcriptional activator that controls the degradation of polysaccharides in plant cell walls. EglC is an 858-amino-acid protein and contains a conserved C-terminal cellulose-binding domain. EglC can be classified in glycoside hydrolase family 74. No homology to any of the endoglucanases from Trichoderma reesei was found. In the plant cell wall xyloglucan is closely linked to cellulose fibrils. We hypothesize that the EglC cellulose-binding domain anchors the enzyme to the cellulose chains while it is cleaving the xyloglucan backbone. By this action it may contribute to the degradation of the plant cell wall structure together with other enzymes, including hemicellulases and cellulases. EglC is most active towards xyloglucan and therefore is functionally different from the other two endoglucanases from A. niger, EglA and EglB, which exhibit the greatest activity towards beta-glucan. Although the mode of action of EglC is not known, this enzyme represents a new enzyme function involved in plant cell wall polysaccharide degradation by A. niger.
 ...
PMID:EglC, a new endoglucanase from Aspergillus niger with major activity towards xyloglucan. 1191 68

Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak (BLS) in rice, an emerging and destructive disease worldwide. Identification of key virulence factors is a prerequisite for understanding the pathogenesis of Xoc. In this study, a Tn5-tagged mutant library of Xoc strain RS105 was screened on rice, and 27 Tn5 mutants were identified that were either non-pathogenic or showed reduced virulence in rice. Fourteen of the non-pathogenic mutants were also unable to elicit the hypersensitive response (HR) in tobacco and were designated Pth(-)/HR(-) mutants; 13 mutants showed attenuated virulence and were able to induce an HR (Vir(-)/HR(+)). Sequence analysis of the Tn5-tagged genes indicated that the 14 Pth(-)/HR(-) mutants included mutations in hrcC, hrcT, hrcV, hpaP, hrcQ, hrpF, hrpG and hrpX. The 13 Vir(-)/HR(+) mutants included tal-C10c-like (a transcriptional activator-like TAL effector), rpfC (regulator of pathogenicity factors), oxyR (oxidative stress transcriptional regulator), dsbC (disulfide isomerase), opgH (glucan biosynthesis glucosyltransferase H), rfbA (glucose-1-phosphate thymidylyltransferase), amtR (aminotransferase), purF (amidophosphoribosyltransferase), thrC (threonine synthase), trpA (tryptophan synthase alpha subunit) and three genes encoding hypothetical proteins (Xoryp_02235, Xoryp_00885 and Xoryp_22910). Collectively, the 27 Tn5 insertions are located in 21 different open reading frames. Bacterial growth and in planta virulence assays demonstrated that opgH, purF, thrC, trpA, Xoryp_02235, Xoryp_00885 and Xoryp_22910 are candidate virulence genes involved in Xoc pathogenesis. Reduced virulence in 13 mutants was restored to wild-type levels when the cognate gene was introduced in trans. Expression profiles demonstrated that the seven candidate virulence genes were significantly induced in planta, although their roles in Xoc pathogenesis remain unclear.
 ...
PMID:Identification of seven Xanthomonas oryzae pv. oryzicola genes potentially involved in pathogenesis in rice. 2207 22