Comparison of the potential membrane insertion geometry's of Escherichia coli low molecular weight penicillin binding protein anchors

1995 ◽  
Vol 23 (1) ◽  
pp. 33S-33S
Author(s):  
Martin G. Roberts ◽  
David A. Phoenix
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Binding Protein ◽  
Membrane Insertion ◽  
Low Molecular Weight ◽  
Penicillin Binding Protein

scholarly journals Purification and Characterization of PBP4a, a New Low-Molecular-Weight Penicillin-Binding Protein fromBacillus subtilis

2001 ◽  
Vol 183 (5) ◽  
pp. 1595-1599 ◽  
Author(s):  
Colette Duez ◽  
Marc Vanhove ◽  
Xavier Gallet ◽  
Fabrice Bouillenne ◽  
Jean-Denis Docquier ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Binding Protein ◽  
Order Rate Constant ◽  
Low Molecular Weight ◽  
Penicillin Binding Protein ◽  
Purification And Characterization ◽  
The Third

ABSTRACT Penicillin-binding protein 4a (PBP4a) from Bacillus subtilis was overproduced and purified to homogeneity. It clearly exhibits dd-carboxypeptidase and thiolesterase activities in vitro. Although highly isologous to the Actinomadura sp. strain R39 DD-peptidase (B. Granier, C. Duez, S. Lepage, S. Englebert, J. Dusart, O. Dideberg, J. van Beeumen, J. M. Frère, and J. M. Ghuysen, Biochem. J. 282:781–788, 1992), which is rapidly inactivated by many β-lactams, PBP4a is only moderately sensitive to these compounds. The second-order rate constant (k 2/K) for the acylation of the essential serine by benzylpenicillin is 300,000 M−1s−1 for the Actinomadura sp. strain R39 peptidase, 1,400 M−1 s−1 for B. subtilis PBP4a, and 7,000 M−1 s−1 forEscherichia coli PBP4, the third member of this class of PBPs. Cephaloridine, however, efficiently inactivates PBP4a (k 2/K = 46,000 M−1 s−1). PBP4a is also much more thermostable than the R39 enzyme.

scholarly journals Characterization of dacC, Which Encodes a New Low-Molecular-Weight Penicillin-Binding Protein in Bacillus subtilis

1998 ◽  
Vol 180 (18) ◽  
pp. 4967-4973 ◽  
Author(s):  
Lotte B. Pedersen ◽  
Thomas Murray ◽  
David L. Popham ◽  
Peter Setlow
Keyword(s):  
Molecular Weight ◽  
Bacillus Subtilis ◽  
Binding Protein ◽  
Low Molecular Weight ◽  
Penicillin Binding Protein ◽  
Wild Type ◽  
Genome Sequencing Project ◽  
Penicillin Binding Proteins ◽  
Sequencing Project

ABSTRACT The pbp gene (renamed dacC), identified by the Bacillus subtilis genome sequencing project, encodes a putative 491-residue protein with sequence homology to low-molecular-weight penicillin-binding proteins. Use of a transcriptional dacC-lacZ fusion revealed thatdacC expression (i) is initiated at the end of stationary phase; (ii) depends strongly on transcription factor ςH; and (iii) appears to be initiated from a promoter located immediately upstream of yoxA, a gene of unknown function located upstream of dacC on the B. subtilis chromosome. A B. subtilis dacCinsertional mutant grew and sporulated identically to wild-type cells, and dacC and wild-type spores had the same heat resistance, cortex structure, and germination and outgrowth kinetics. Expression ofdacC in Escherichia coli showed that this gene encodes an ∼59-kDa membrane-associated penicillin-binding protein which is highly toxic when overexpressed.

Rap1b Association with the Platelet Cytoskeleton Occurs in the Absence of Glycoproteins IIb/IIIa

1998 ◽  
Vol 79 (04) ◽  
pp. 832-836 ◽  
Author(s):  
Thomas Fischer ◽  
Christina Duffy ◽  
Gilbert White
Keyword(s):  
Molecular Weight ◽  
Divalent Cation ◽  
Binding Proteins ◽  
Binding Protein ◽  
Platelet Membrane ◽  
Low Molecular Weight ◽  
Membrane Glycoproteins ◽  
Gtp Binding Protein ◽  
Gtp Binding Proteins ◽  
Gtp Binding

SummaryPlatelet membrane glycoproteins (GP) IIb/IIIa and rap1b, a 21 kDa GTP binding protein, associate with the triton-insoluble, activation-dependent platelet cytoskeleton with similar rates and divalent cation requirement. To examine the possibility that GPIIb/IIIa was required for rap1b association with the cytoskeleton, experiments were performed to determine if the two proteins were linked under various conditions. Chromatography of lysates from resting platelets on Sephacryl S-300 showed that GPIIb/IIIa and rap1b were well separated and distinct proteins. Immunoprecipitation of GPIIb/IIIa from lysates of resting platelets did not produce rap1b or other low molecular weight GTP binding proteins and immunoprecipitation of rap1b from lysates of resting platelets did not produce GPIIb/IIIa. Finally, rap1b was associated with the activation-dependent cytoskeleton of platelets from a patient with Glanzmann’s thrombasthenia who lacks surface expressed glycoproteins IIb and IIIa. Based on these findings, we conclude that no association between GPIIb/IIIa and rap1b is found in resting platelets and that rap1b association with the activation-dependent cytoskeleton is at least partly independent of GPIIb/IIIa.

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