Structural and functional characterization of Salmonella enterica serovar Typhimurium YcbL: an unusual Type II glyoxalase.

YcbL has been annotated as either a metallo-β-lactamase or glyoxalase II (GLX2), both members of the zinc metallohydrolase superfamily, that contains many enzymes with a diverse range of activities. Here, we report crystallographic and biochemical data for Salmonella enterica serovar Typhimurium YcbL that establishes it as GLX2, which differs in certain structural and functional properties compared with previously known examples. These features include the insertion of an α-helix after residue 87 in YcbL and truncation of the C-terminal domain, which leads to the loss of some recognition determinants for the glutathione substrate.

Comprehensive identification of essential Staphylococcus aureus genes using Transposon-Mediated Differential Hybridisation (TMDH).

Background: In recent years there has been an increasing problem with Staphylococcus aureus strains that are resistant to treatment with existing antibiotics. An important starting point for the development of new antimicrobial drugs is the identification of "essential" genes that are important for bacterial survival and growth.

Results: We have developed a robust microarray and PCR-based method, Transposon-Mediated Differential Hybridisation (TMDH), that uses novel bioinformatics to identify transposon inserts in genome-wide libraries.

Functional analysis of the GTPases EngA and YhbZ encoded by Salmonella typhimurium.

The S. typhimurium genome encodes proteins, designated EngA and YhbZ, which have a high sequence identity with the GTPases EngA/Der and ObgE/CgtAE of Escherichia coli. The wild-type activity of the E.

RSV604, a novel inhibitor of respiratory syncytial virus replication.

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections worldwide, yet no effective vaccine or antiviral treatment is available. Here we report the discovery and initial development of RSV604, a novel benzodiazepine with submicromolar anti-RSV activity. It proved to be equipotent against all clinical isolates tested of both the A and B subtypes of the virus.

Structure of Staphylococcus aureus guanylate monophosphate kinase.

Nucleotide monophosphate kinases (NMPKs) are potential antimicrobial drug targets owing to their role in supplying DNA and RNA precursors. The present work reports the crystal structure of Staphylococcus aureus guanylate monophosphate kinase (SaGMK) at 1.9 A resolution.

Structures of R- and T-state Escherichia coli aspartokinase III. Mechanisms of the allosteric transition and inhibition by lysine.

Aspartokinase III (AKIII) from Escherichia coli catalyzes an initial commitment step of the aspartate pathway, giving biosynthesis of certain amino acids including lysine. We report crystal structures of AKIII in the inactive T-state with bound feedback allosteric inhibitor lysine and in the R-state with aspartate and ADP. The structures reveal an unusual configuration for the regulatory ACT domains, in which ACT2 is inserted into ACT1 rather than the expected tandem repeat.

Structure of Staphylococcus aureus cytidine monophosphate kinase in complex with cytidine 5'-monophosphate.

The crystal structure of Staphylococcus aureus cytidine monophosphate kinase (CMK) in complex with cytidine 5'-monophosphate (CMP) has been determined at 2.3 angstroms resolution. The active site reveals novel features when compared with two orthologues of known structure.

1,4-Benzodiazepines as inhibitors of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is the cause of one-fifth of all lower respiratory tract infections worldwide and is increasingly being recognized as a serious threat to patient groups with poorly functioning immune systems. Our approach to finding a novel inhibitor of this virus was to screen a 20 000-member diverse library in a whole cell XTT assay. Parallel assays were carried out in the absence of virus in order to quantify any associated cell toxicity.

Structures of S. aureus thymidylate kinase reveal an atypical active site configuration and an intermediate conformational state upon substrate binding.

Methicillin-resistant Staphylococcus aureus (MRSA) poses a major threat to human health, particularly through hospital acquired infection. The spread of MRSA means that novel targets are required to develop potential inhibitors to combat infections caused by such drug-resistant bacteria. Thymidylate kinase (TMK) is attractive as an antibacterial target as it is essential for providing components for DNA synthesis.

GTP cyclohydrolase II structure and mechanism.

GTP cyclohydrolase II converts GTP to 2,5-diamino-6-beta-ribosyl-4(3H)-pyrimidinone 5'-phosphate, formate and pyrophosphate, the first step in riboflavin biosynthesis. The essential role of riboflavin in metabolism and the absence of GTP cyclohydrolase II in higher eukaryotes makes it a potential novel selective antimicrobial drug target. GTP cyclohydrolase II catalyzes a distinctive overall reaction from GTP cyclohydrolase I; the latter converts GTP to dihydroneopterin triphosphate, utilized in folate and tetrahydrobiopterin biosynthesis.

Crystallographic studies of shikimate binding and induced conformational changes in Mycobacterium tuberculosis shikimate kinase.

The X-ray crystal structure of Mycobacterium tuberculosis shikimate kinase (SK) with bound shikimate and adenosine diphosphate (ADP) has been determined to a resolution of 2.15 A. The binding of shikimate in a shikimate kinase crystal structure has not previously been reported.