CaltechAUTHORS
  A Caltech Library Service

Assembly and Architecture of Gram-Positive and -Negative Cell Walls

Gumbart, James C. and Beeby, Morgan and Jensen, Grant and Roux, Benoit (2013) Assembly and Architecture of Gram-Positive and -Negative Cell Walls. Biophysical Journal, 104 (2). 642A-642A. ISSN 0006-3495. http://resolver.caltech.edu/CaltechAUTHORS:20130425-135202813

[img]
Preview
PDF - Published Version
See Usage Policy.

36Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20130425-135202813

Abstract

The cell wall, a porous mesh-like structure, provides shape and physical protection for bacteria. At the atomic level, it is composed of peptidoglycan (PG), a polymer of stiff glycan strands cross-linked by short, flexible peptides. However, at the mesoscale, multiple models for the organization of PG have been put forth, distinguished by glycan strands parallel to the cell surface (the so-called "layered'' model) or perpendicular (the “scaffold” model). To test these models, and to resolve the mechanical properties of PG, we have built and simulated at an atomic scale patches of both Gram-positive and negative cell walls in different organizations up to 50 nanometers in size. In the case of Gram-positive PG, molecular dynamics simulations of the layered model are found to elucidate the mechanisms behind a distinct curling effect observed in three-dimensional electron cryo-tomography images of fragmented cell walls. For Gram-negative PG, simulations of patches with different average-glycan-strand lengths reveal an anisotropic elasticity, in good agreement with atomic-force microscopy experiments. Insights from the simulations reveal how mesoscopic and macroscopic properties of a ubiquitous bacterial ultrastructure arise from its atomic-scale interactions and organization.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/j.bpj.2012.11.3544DOIUNSPECIFIED
http://www.sciencedirect.com/science/article/pii/S000634951204790XPublisherUNSPECIFIED
Additional Information:© 2013 Biophysical Society. Published by Elsevier Inc.
Record Number:CaltechAUTHORS:20130425-135202813
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20130425-135202813
Official Citation:James C. Gumbart, Morgan Beeby, Grant Jensen, Benoit Roux, Assembly and Architecture of Gram-Positive and -Negative Cell Walls, Biophysical Journal, Volume 104, Issue 2, Supplement 1, 29 January 2013, Page 642a, ISSN 0006-3495, 10.1016/j.bpj.2012.11.3544.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38121
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:03 May 2013 21:47
Last Modified:04 Aug 2014 20:01

Repository Staff Only: item control page