Fishovitz J.,Nieuwland Science Hall |
Hermoso J.A.,CSIC - Institute of Physical Chemistry "Rocasolano" |
Chang M.,Nieuwland Science Hall |
Mobashery S.,Nieuwland Science Hall
IUBMB Life | Year: 2014
High-level resistance to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA) is due to expression of penicillin-binding protein 2a (PBP2a), a transpeptidase that catalyzes cell-wall crosslinking in the face of the challenge by β-lactam antibiotics. The activity of this protein is regulated by allostery at a site 60 Å distant from the active site, where crosslinking of cell wall takes place. This review discusses the state of knowledge on this important enzyme of cell-wall biosynthesis in MRSA. © 2014 IUBMB Life, 66(8):572-577, 2014 © 2014 International Union of Biochemistry and Molecular Biology.
Artola-Recolons C.,CSIC - Institute of Physical Chemistry "Rocasolano" |
Llarrull L.I.,Nieuwland Science Hall |
Lastochkin E.,Nieuwland Science Hall |
Mobashery S.,Nieuwland Science Hall |
Hermoso J.A.,CSIC - Institute of Physical Chemistry "Rocasolano"
Acta Crystallographica Section F: Structural Biology and Crystallization Communications | Year: 2011
MltE from Escherichia coli (193 amino acids, 21 380 Da) is a lytic trans-glycosylase that initiates the first step of cell-wall recycling. This enzyme is responsible for the cleavage of the cell-wall peptidoglycan at the Β-1,4-glycosidic bond between the N-acetylglucosamine and N-acetylmuramic acid units. At the end this reaction generates a disaccharide that is internalized and initiates the recycling process. To obtain insights into the biological functions of MltE, crystallization trials were performed and crystals of MltE protein that were suitable for X-ray diffraction analysis were obtained. The MltE protein of E. coli was crystallized using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture consisting of 28% polyethylene glycol 4000, 0.1 M Tris pH 8.4 and 0.2 M magnesium chloride. Further optimization was performed using the microbatch technique. Single crystals were obtained that belonged to the orthorhombic space group C2221, with unit-cell parameters a = 123.32, b = 183.93, c = 35.29 Å, and diffracted to a resolution of 2.1 Å. © 2011 International Union of Crystallography. All rights reserved.