temporary banners

 




 

Journal Issue - Volume 18 Issue 1 (January 2009)

  • In this issue

  • Published in Wiley Interscience on Dec 17, 2008
  • DOI: 10.1002/pro.40 (p vii)

No abstract.

  • Editorial

  • Brian Matthews
  • Published in Wiley Interscience on Dec 03, 2008
  • DOI: 10.1002/pro.22 (p 1)

No Abstract.

No abstract.

The polyproteins of coronaviruses are cleaved by viral proteases into at least 15 nonstructural proteins (Nsps). Consisting of five domains, Nsp3 is the largest of these (180-210 kDa). Among these domains, the so-called X-domain is believed to act as ADP-ribose-1-phosphate phosphatase or to bind poly(ADP-ribose). However, here we show that the X-domain of Infectious Bronchitis Virus (strain Beaudette), a Group-3 coronavirus, fails to bind ADP-ribose. This is explained on the basis of the...

The binding of the Bacillus anthracis protective antigen (PA) to the host cell receptor is the first step toward the formation of the anthrax toxin, a tripartite set of proteins that include the enzymatic moieties edema factor (EF), and lethal factor (LF). PA is cleaved by a furin-like protease on the cell surface followed by the formation of a donut-shaped heptameric prepore. The prepore undergoes a major structural transition at acidic pH that results in the formation of a membrane spanning...

Trehalose is a ubiquitous molecule that occurs in lower and higher life forms but not in mammals. Till about 40 years ago, trehalose was visualized as a storage molecule, aiding the release of glucose for carrying out cellular functions. This perception has now changed dramatically. The role of trehalose has expanded, and this molecule has now been implicated in a variety of situations. Trehalose is synthesized as a stress-responsive factor when cells are exposed to environmental stresses like...

Although there is X-ray crystallographic evidence that the interaction between major histocompatibility complex (MHC, in humans HLA) class I molecules and T cell receptors (TCR) or killer cell Ig-like receptors (KIR) may be accompanied by considerable changes in the conformation of selected residues or even entire loops within TCR or KIR, conformational changes between receptor-bound and -unbound MHC class I molecules of comparable magnitude have not been observed so far. We have previously...

A specialized class of RNases shows a high cytotoxicity toward tumor cell lines, which is critically dependent on their ability to reach the cytosol and to evade the action of the ribonuclease inhibitor (RI). The cytotoxicity and antitumor activity of bovine seminal ribonuclease (BSRNase), which exists in the native state as an equilibrium mixture of a swapped and an unswapped dimer, are peculiar properties of the swapped form. A dimeric variant (HHP2-RNase) of human pancreatic RNase, in which...

thumbnail image:

The Notch ankyrin domain is a repeat protein whose folding has been characterized through equilibrium and kinetic measurements. In previous work, equilibrium folding free energies of truncated constructs were used to generate an experimentally determined folding energy landscape (Mello and Barrick, Proc Natl Acad Sci USA 2004;101:14102-14107). Here, this folding energy landscape is used to parameterize a kinetic model in which local transition probabilities between partly folded states are...

Bacterial microcompartments are supramolecular protein assemblies that function as bacterial organelles by compartmentalizing particular enzymes and metabolic intermediates. The outer shells of these microcompartments are assembled from multiple paralogous structural proteins. Because the paralogs are required to assemble together, their genes are often transcribed together from the same operon, giving rise to a distinctive genomic pattern: multiple, typically small, paralogous proteins encoded...

Checkpoint kinase 2 (Chk2), a ser/thr kinase involved in the ATM-Chk2 checkpoint pathway, is activated by genomic instability and DNA damage and results in either arrest of the cell cycle to allow DNA repair to occur or apoptosis if the DNA damage is severe. Drugs that specifically target Chk2 could be beneficial when administered in combination with current DNA-damaging agents used in cancer therapy. Recently, a novel inhibitor of Chk2, NSC 109555, was identified that exhibited high potency...

We examine the contribution of residues at the dimer interface of the transcriptional regulator OxyR to oligomerization. Residues in contact across the dimer interface of OxyR were identified using the program Quaternary Contacts (QContacts). Site-directed mutagenesis was performed on the non-alanine or glycine residues identified in the resultant contact profile and the oligomerization ability of the mutant proteins was tested using the cI repressor system to identify residues that are hot...

Carboxysomes are primitive bacterial organelles that function as a part of a carbon concentrating mechanism (CCM) under conditions where inorganic carbon is limiting. The carboxysome enhances the efficiency of cellular carbon fixation by encapsulating together carbonic anhydrase and the CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The carboxysome has a roughly icosahedral shape with an outer shell between 800 and 1500 Å in diameter, which is constructed from a...

Green fluorescent protein (GFP) fusion proteins provide a potentially facile tool for identification of well expressed, properly behaved membrane proteins for biochemical and structural study. Here, we present a GFP-expression survey of 300 membrane proteins from 18 bacterial and archaeal extremophiles, organisms expected to be rich sources of membrane proteins having robust biophysical properties. We find that GFP-fusion fluorescence intensity is an excellent indicator of over-expression...

The structural characterization of small integral membrane proteins pose a significant challenge for structural biology because of the multitude of molecular interactions between the protein and its heterogeneous environment. Here, the three-dimensional backbone structure of Rv1761c from Mycobacterium tuberculosis has been characterized using solution NMR spectroscopy and dodecylphosphocholine (DPC) micelles as a membrane mimetic environment. This 127 residue single transmembrane helix protein...

Page:   1 2 Next