Proton-transfer effects in the active-site region of Escherichia coli thioredoxin using two-dimensional proton NMR

Biochemistry ◽  
1991 ◽  
Vol 30 (17) ◽  
pp. 4262-4268 ◽  
Author(s):  
H. Jane Dyson ◽  
Linda L. Tennant ◽  
Arne Holmgren
Keyword(s):  
Escherichia Coli ◽  
Proton Transfer ◽  
Active Site ◽  
Proton Nmr ◽  
Two Dimensional ◽  
Transfer Effects ◽  
Active Site Region

One- and two-dimensional proton NMR studies of the active site of iron(II) superoxide dismutase from Escherichia coli

1994 ◽  
Vol 33 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Li June Ming ◽  
John B. Lynch ◽  
Richard C. Holz ◽  
Lawrence Que
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Active Site ◽  
Proton Nmr ◽  
Two Dimensional ◽  
Nmr Studies

scholarly journals Environment of the Active Site Region of RseP, an Escherichia coli Regulated Intramembrane Proteolysis Protease, Assessed by Site-directed Cysteine Alkylation

2006 ◽  
Vol 282 (7) ◽  
pp. 4553-4560 ◽  
Author(s):  
Kayo Koide ◽  
Saki Maegawa ◽  
Koreaki Ito ◽  
Yoshinori Akiyama
Keyword(s):  
Escherichia Coli ◽  
Stress Responses ◽  
Active Site ◽  
Molecular Mechanisms ◽  
Lipid Phase ◽  
Intramembrane Proteolysis ◽  
Regulated Intramembrane Proteolysis ◽  
Eukaryotic Organisms ◽  
Alkylating Reagents ◽  
Active Site Region

Regulated intramembrane proteolysis (RIP) plays crucial roles in both prokaryotic and eukaryotic organisms. Proteases for RIP cleave transmembrane regions of substrate membrane proteins. However, the molecular mechanisms for the proteolysis of membrane-embedded transmembrane sequences are largely unknown. Here we studied the environment surrounding the active site region of RseP, an Escherichia coli S2P ortholog involved in the σE pathway of extracytoplasmic stress responses. RseP has two presumed active site motifs, HEXXH and LDG, located in membrane-cytoplasm boundary regions. We examined the reactivity of cysteine residues introduced within or in the vicinity of these two active site motifs with membrane-impermeable thiol-alkylating reagents under various conditions. The active site positions were inaccessible to the reagents in the native state, but many of them became partially modifiable in the presence of a chaotrope, while requiring simultaneous addition of a chaotrope and a detergent for full modification. These results suggest that the active site of RseP is not totally embedded in the lipid phase but located within a proteinaceous structure that is partially exposed to the aqueous milieu.

scholarly journals Interplay of nucleophilic catalysis with proton transfer in the nitrile reductase QueF from Escherichia coli

2019 ◽  
Vol 9 (3) ◽  
pp. 842-853 ◽  
Author(s):  
Jihye Jung ◽  
Jan Braun ◽  
Tibor Czabany ◽  
Bernd Nidetzky
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Active Site ◽  
Nucleophilic Catalysis ◽  
Proton Relay ◽  
Network Of Hydrogen Bonds ◽  
Site Network ◽  
Nitrile Reduction ◽  
Enzyme Intermediate

Proton relay through an active-site network of hydrogen bonds promotes enzymatic nitrile reduction to amine via a covalent thioimidate enzyme intermediate.

scholarly journals Structure of peptide from active site region of Escherichia coli L-asparaginase.

1977 ◽  
Vol 252 (6) ◽  
pp. 2072-2076
Author(s):  
R G Peterson ◽  
F F Richards ◽  
R E Handschumacher
Keyword(s):  
Escherichia Coli ◽  
Active Site ◽  
Active Site Region

scholarly journals DksA regulates RNA polymerase in Escherichia coli through a network of interactions in the secondary channel that includes Sequence Insertion 1

2015 ◽  
Vol 112 (50) ◽  
pp. E6862-E6871 ◽  
Author(s):  
Andrey Parshin ◽  
Anthony L. Shiver ◽  
Jookyung Lee ◽  
Maria Ozerova ◽  
Dina Schneidman-Duhovny ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Active Site ◽  
Amino Acid Starvation ◽  
Cross Linking ◽  
Molecular Function ◽  
Secondary Channel ◽  
Global Response ◽  
Microbial Life ◽  
Active Site Region

Sensing and responding to nutritional status is a major challenge for microbial life. In Escherichia coli, the global response to amino acid starvation is orchestrated by guanosine-3′,5′-bisdiphosphate and the transcription factor DksA. DksA alters transcription by binding to RNA polymerase and allosterically modulating its activity. Using genetic analysis, photo–cross-linking, and structural modeling, we show that DksA binds and acts upon RNA polymerase through prominent features of both the nucleotide-access secondary channel and the active-site region. This work is, to our knowledge, the first demonstration of a molecular function for Sequence Insertion 1 in the β subunit of RNA polymerase and significantly advances our understanding of how DksA binds to RNA polymerase and alters transcription.

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