scholarly journals Kinetic and Structural Characterization of Tunnel-Perturbing Mutants in Bradyrhizobium japonicum Proline Utilization A

Biochemistry ◽  
2014 ◽  
Vol 53 (31) ◽  
pp. 5150-5161 ◽  
Author(s):  
Benjamin W. Arentson ◽  
Min Luo ◽  
Travis A. Pemberton ◽  
John J. Tanner ◽  
Donald F. Becker
Keyword(s):  
Structural Characterization ◽  
Bradyrhizobium Japonicum ◽  
Proline Utilization ◽  
Proline Utilization A

A STUDY ON KINETIC CHARACTERIZATION OF CHANNEL-BLOCKING MUTANTS IN BRADYRHIZOBIUM JAPONICUM UTILIZATION A

2021 ◽  
pp. 49-52
Author(s):  
Anand Shanker Singh ◽  
G. Radhika ◽  
R. Praveen Kumar ◽  
Debarshi Jana
Keyword(s):  
Active Site ◽  
Bradyrhizobium Japonicum ◽  
Kinetic Data ◽  
Active Sites ◽  
Substrate Channeling ◽  
Site Analysis ◽  
Proline Utilization ◽  
Channel Blocking ◽  
Proline Utilization A

Proline utilization A (PutA) from Bradyrhizobium japonicum (BjPutA) is a bifunctional avoenzyme that catalyzes the oxidation of proline to glutamate using fused proline dehydrogenase (PRODH) and ∆1-pyrroline-5-carboxylate dehydrogenase (P5CDH) domains. Recent crystal structures and kinetic data suggest an intramolecular channel connects the two active sites, promoting substrate channeling of the intermediate P5C from the PRODH domain to the P5CDH domain. In this work several mutations were made along the channel in an effort to block passage of P5C to the second active site. Analysis of several site-specic mutants in the substrate channel of BjPutA revealed an important role for D779 in the channeling path. BjPutA mutants D779Y and D779W signicantly decreased the overall PRODH-P5CDH channeling reaction indicating that bulky mutations at residue D779 impede travel of P5C through the channel. Interestingly, D779Y and D779W also exhibited lower P5CDH activity, suggesting that exogenous P5C must enter the channel upstream of D779. Replacing D779 with a smaller residue (D779A) had no effect on the catalytic and channeling properties of BjPutA showing that the carboxylate group of D779 is not essential for channeling. An identical mutation at D778 (D778Y) did not impact BjPutA channeling activity. Thus, D779 is optimally orientated so that replacement with the larger side chains of Tyr/Trp blocks P5C movment through the channel. The kinetic data reveal not only that bulky mutations at residue D779 hinder passage of P5C to the second active site, but also P5C must use the channel to efciently access the P5CDH domain. Moreover, these mutants may be used to learn more about the hydrolysis event that is thought to take place within the channel

scholarly journals Structure and characterization of a class 3B proline utilization A: Ligand-induced dimerization and importance of the C-terminal domain for catalysis

2017 ◽  
Vol 292 (23) ◽  
pp. 9652-9665 ◽  
Author(s):  
David A. Korasick ◽  
Thameesha T. Gamage ◽  
Shelbi Christgen ◽  
Kyle M. Stiers ◽  
Lesa J. Beamer ◽  
...  
Keyword(s):  
Terminal Domain ◽  
Proline Utilization ◽  
Proline Utilization A

scholarly journals Crystal structure of the bifunctional proline utilization A flavoenzyme from Bradyrhizobium japonicum

2010 ◽  
Vol 107 (7) ◽  
pp. 2878-2883 ◽  
Author(s):  
D. Srivastava ◽  
J. P. Schuermann ◽  
T. A. White ◽  
N. Krishnan ◽  
N. Sanyal ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bradyrhizobium Japonicum ◽  
Proline Utilization ◽  
Proline Utilization A

scholarly journals Kinetic characterization of proline utilization A (PutA) using proline analogues

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
YiZi Mao ◽  
Javier Seravalli ◽  
John Tanner ◽  
Donald Becker
Keyword(s):  
Kinetic Characterization ◽  
Proline Utilization ◽  
Proline Utilization A

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

Structural characterization of the PPIase domain of FKBP51, a cochaperone of human Hsp90

2011 ◽  
Vol 44 (06) ◽  
Author(s):  
A Bracher ◽  
C Kozany ◽  
AK Thost ◽  
F Hausch
Keyword(s):  
Structural Characterization ◽  
Ppiase Domain

Structural characterization of dendrobine-type sesquiterpene alkaloids from the stems of Dendrobium nobile using LC-MS/MS

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
YH Wang ◽  
B Avula ◽  
N Abe ◽  
F Wei ◽  
M Wang ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Dendrobium Nobile
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