Type I polyketide biosynthesis in bacteria (Part A — erythromycin biosynthesis) (1994 to 2000)

2001 ◽  
Vol 18 (2) ◽  
pp. 190-227 ◽  
Author(s):  
Bernard J. Rawlings
Keyword(s):  
Type I ◽  
Polyketide Biosynthesis ◽  
Erythromycin Biosynthesis

ChemInform Abstract: Type I Polyketide Biosynthesis in Bacteria (Part B)

ChemInform ◽  
2010 ◽  
Vol 32 (37) ◽  
pp. no-no
Author(s):  
Bernard J. Rawlings
Keyword(s):  
Type I ◽  
Polyketide Biosynthesis

scholarly journals Computationally-guided exchange of substrate selectivity motifs in a modular polyketide synthase acyltransferase

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Edward Kalkreuter ◽  
Kyle S. Bingham ◽  
Aaron M. Keeler ◽  
Andrew N. Lowell ◽  
Jennifer J. Schmidt ◽  
...  
Keyword(s):  
Active Site ◽  
Polyketide Synthase ◽  
Polyketide Synthases ◽  
Substrate Selectivity ◽  
Substrate Selection ◽  
Polyketide Biosynthesis ◽  
Erythromycin Biosynthesis ◽  
Malonyl Coa ◽  
Modular Polyketide Synthase ◽  
Dynamics Simulations

AbstractPolyketides, one of the largest classes of natural products, are often clinically relevant. The ability to engineer polyketide biosynthesis to produce analogs is critically important. Acyltransferases (ATs) of modular polyketide synthases (PKSs) catalyze the installation of malonyl-CoA extenders into polyketide scaffolds. ATs have been targeted extensively to site-selectively introduce various extenders into polyketides. Yet, a complete inventory of AT residues responsible for substrate selection has not been established, limiting the scope of AT engineering. Here, molecular dynamics simulations are used to prioritize ~50 mutations within the active site of EryAT6 from erythromycin biosynthesis, leading to identification of two previously unexplored structural motifs. Exchanging both motifs with those from ATs with alternative extender specificities provides chimeric PKS modules with expanded and inverted substrate specificity. Our enhanced understanding of AT substrate selectivity and application of this motif-swapping strategy are expected to advance our ability to engineer PKSs towards designer polyketides.

Polyketide Biosynthesis beyond the Type I, II, and III Polyketide Synthase Paradigms: A Progress Report

2007 ◽  
pp. 154-166 ◽  
Author(s):  
Ben Shen ◽  
Yi-Qiang Cheng ◽  
Steven D. Christenson ◽  
Hui Jiang ◽  
Jianhua Ju ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Progress Report ◽  
Type I ◽  
Polyketide Biosynthesis

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Two Distinct Types of Microfilaments in the Cytoplasm of Human Adenohypophysial Cells

1973 ◽  
Vol 31 ◽  
pp. 668-669
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
I. E. Stratmann ◽  
C. Ezrin
Keyword(s):  
Pituitary Tumors ◽  
Average Diameter ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Type I ◽  
Breast Cancer Patients ◽  
Human Pituitary ◽  
Severe Diabetes ◽  
Pituitary Glands ◽  
Membrane Bound

Surgically removed human pituitary glands as well as pituitary tumors fixed in glutaraldehyde, postfixed in osmium tetroxide, embedded in epon resin, stained with uranyl acetate and lead citrate have been investigated by electron microscopy in order to correlate ultrastructure with functional activity. In the course of this study two distinct types of microfilaments have been identified in the cytoplasm of adenohypophysiocytes.Type I microfilaments (Fig. 1) were found in the cytoplasm of anterior lobe cells of five female subjects with disseminated mammary cancer and two patients with severe diabetes mellitus. The breast cancer patients were treated pre-operatively for various periods of time with different doses of oxysteroids. The microfilaments had an average diameter of JO A, formed parallel bundles, were scattered irregularly in the cytoplasm and were frequently located in the perikaryon. They were not membrane-bound and failed to show any periodicity.

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