Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the adaptive mechanisms allowing the gastric pathogen Helicobacter pylori to survive acid shocks have been well documented, the mechanisms allowing growth at mildly acidic conditions (pH approximately 5.5) are still poorly understood. Here we demonstrate that H. pylori strain 26695 increases the transcription and activity of its urease, amidase, and formamidase enzymes four- to ninefold in response to growth at pH 5.5. Supplementation of growth medium with NiCl2 resulted in a similar induction of urease activity (at low NiCl2 concentration) and amidase activity (at > or = 500 micro M NiCl2) but did not affect formamidase activity. Mutation of the fur gene, which encodes an iron-responsive repressor of both amidases, resulted in a constitutively high level of amidase and formamidase activity at either pH but did not affect urease activity at pH 7.0 or pH 5.5. In contrast, mutation of the nikR gene, encoding the nickel-responsive activator of urease expression, resulted in a significant reduction of acid-responsive induction of amidase and formamidase activity. Finally, acid-responsive repression of fur transcription was absent in the H. pylori nikR mutant, whereas transcription of the nikR gene itself was increased at pH 5.5 in wild-type H. pylori. We hypothesize that H. pylori uses a repressor cascade to respond to low pH, with NikR initiating the response directly via the urease operon and indirectly via the members of the Fur regulon.
 ...
PMID:Acid-responsive gene induction of ammonia-producing enzymes in Helicobacter pylori is mediated via a metal-responsive repressor cascade. 1474 19

1-Aminocyclopropane-1-carboxylate (ACC) deaminase, which is encoded by some bacteria, can reduce the amount of ethylene, a root elongation inhibitor, and stimulate the growth of plants under various environmental stresses. The presence of ACC deaminase activity and the regulation of ACC in several rhizospheric bacteria have been reported. The nitrogen-fixing Pseudomonas stutzeri A1501 is capable of endophytic association with rice plants and promotes the growth of rice. However, the functional identification of ACC deaminase has not been performed. In this study, the proposed effect of ACC deaminase in P. stutzeri A1501 was investigated. Genome mining showed that P. stutzeri A1501 carries a single gene encoding ACC deaminase, designated acdS. The acdS mutant was devoid of ACC deaminase activity and was less resistant to NaCl and NiCl2 compared with the wild-type. Furthermore, inactivation of acdS greatly impaired its nitrogenase activity under salt stress conditions. It was also observed that mutation of the acdS gene led to loss of the ability to promote the growth of rice under salt or heavy metal stress. Taken together, this study illustrates the essential role of ACC deaminase, not only in enhancing the salt or heavy metal tolerance of bacteria but also in improving the growth of plants, and provides a theoretical basis for studying the interaction between plant growth-promoting rhizobacteria and plants.
...
PMID:1-Aminocyclopropane-1-Carboxylate Deaminase from Pseudomonas stutzeri A1501 Facilitates the Growth of Rice in the Presence of Salt or Heavy Metals. 2567 2