Kinetic and Structural Analysis of Active Site Mutants of Monofunctional NAD-Dependent 5,10-Methylenetetrahydrofolate Dehydrogenase fromSaccharomyces cerevisiae†

Biochemistry ◽  
2005 ◽  
Vol 44 (39) ◽  
pp. 13163-13171 ◽  
Author(s):  
Wendi Wagner ◽  
Andrew P. Breksa ◽  
Arthur F. Monzingo ◽  
Dean R. Appling ◽  
Jon D. Robertus
Keyword(s):  
Structural Analysis ◽  
Active Site ◽  
Methylenetetrahydrofolate Dehydrogenase ◽  
Active Site Mutants

scholarly journals Oligoribonuclease is the primary degradative enzyme for pGpG inPseudomonas aeruginosathat is required for cyclic-di-GMP turnover

2015 ◽  
Vol 112 (36) ◽  
pp. E5048-E5057 ◽  
Author(s):  
Mona W. Orr ◽  
Gregory P. Donaldson ◽  
Geoffrey B. Severin ◽  
Jingxin Wang ◽  
Herman O. Sintim ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Active Site ◽  
Half Life ◽  
Biofilm Formation ◽  
Degradation Pathway ◽  
Dependent Manner ◽  
Capillary Action ◽  
Diguanylate Cyclases ◽  
Active Site Mutants ◽  
Degradative Enzyme

The bacterial second messenger cyclic di-GMP (c-di-GMP) controls biofilm formation and other phenotypes relevant to pathogenesis. Cyclic-di-GMP is synthesized by diguanylate cyclases (DGCs). Phosphodiesterases (PDE-As) end signaling by linearizing c-di-GMP to 5ʹ-phosphoguanylyl-(3ʹ,5ʹ)-guanosine (pGpG), which is then hydrolyzed to two GMP molecules by yet unidentified enzymes termed PDE-Bs. We show that pGpG inhibits a PDE-A fromPseudomonas aeruginosa. In a dual DGC and PDE-A reaction, excess pGpG extends the half-life of c-di-GMP, indicating that removal of pGpG is critical for c-di-GMP homeostasis. Thus, we sought to identify the PDE-B enzyme(s) responsible for pGpG degradation. A differential radial capillary action of ligand assay-based screen for pGpG binding proteins identified oligoribonuclease (Orn), an exoribonuclease that hydrolyzes two- to five-nucleotide-long RNAs. Purified Orn rapidly converts pGpG into GMP. To determine whether Orn is the primary enzyme responsible for degrading pGpG, we assayed cell lysates of WT and ∆ornstrains ofP. aeruginosaPA14 for pGpG stability. The lysates from ∆ornshowed 25-fold decrease in pGpG hydrolysis. Complementation with WT, but not active site mutants, restored hydrolysis. Accumulation of pGpG in the ∆ornstrain could inhibit PDE-As, increasing c-di-GMP concentration. In support, we observed increased transcription from the c-di-GMP–regulatedpelpromoter. Additionally, the c-di-GMP–governed auto-aggregation and biofilm phenotypes were elevated in the ∆ornstrain in apel-dependent manner. Finally, we directly detect elevated pGpG and c-di-GMP in the ∆ornstrain. Thus, we identified that Orn serves as the primary PDE-B enzyme that removes pGpG, which is necessary to complete the final step in the c-di-GMP degradation pathway.

scholarly journals Expression and characterization of active site mutants of hevamine, a chitinase from the rubber tree Hevea brasiliensis

2002 ◽  
Vol 269 (3) ◽  
pp. 893-901 ◽  
Author(s):  
Evert Bokma ◽  
Henriëtte J. Rozeboom ◽  
Mark Sibbald ◽  
Bauke W. Dijkstra ◽  
Jaap J. Beintema
Keyword(s):  
Active Site ◽  
Hevea Brasiliensis ◽  
Rubber Tree ◽  
Active Site Mutants

scholarly journals Active site mutants of human secreted Group IIA Phospholipase A2 lacking hydrolytic activity retain their bactericidal effect

Biochimie ◽  
2012 ◽  
Vol 94 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Lucimara Chioato ◽  
Elisangela Aparecida Aragão ◽  
Tatiana Lopes Ferreira ◽  
Richard J. Ward
Keyword(s):  
Phospholipase A2 ◽  
Active Site ◽  
Hydrolytic Activity ◽  
Bactericidal Effect ◽  
Active Site Mutants ◽  
Group Iia Phospholipase A2

ACTIVE-SITE MUTANTS OF THE GLUTATHIONE REDUCTASE FROM ESCHERICHIA COLI

1991 ◽  
pp. 525-528
Author(s):  
M. P. Deonarain ◽  
N. S. Scrutton ◽  
A. Berry ◽  
R. N. Perham
Keyword(s):  
Escherichia Coli ◽  
Glutathione Reductase ◽  
Active Site ◽  
Active Site Mutants
Sign in / Sign up

Export Citation Format

Share Document