Replacement of catalytic histidine-195 of chloramphenicol acetyltransferase: Evidence for a general base role for glutamate

Lewendon, Ann; Murray, Iain A.; Shaw, William V.; Gibbs, M.R.J.; Leslie, Andrew G. W.

doi:10.1021/bi00173a043

Cited by 72 publications

(70 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…By analogy with CAT, a prototype AT, H124 of PapA5 would be expected to act as the catalytic base (41). By the same criterion, D128 in PapA5 should be required as an active site stabilizer (38,42 (38,41). Mutational analysis of the proposed PapA5 catalytic site motif is consistent with the catalytic mechanism proposed for CAT and other ATs.…”

Section: Discussionmentioning

confidence: 53%

See 1 more Smart Citation

Mycobacterial polyketide-associated proteins are acyltransferases: Proof of principle with Mycobacterium tuberculosis PapA5

Onwueme

Ferreras

Buglino

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Mycobacterium tuberculosis (Mt) produces complex virulence-enhancing lipids with scaffolds consisting of phthiocerol and phthiodiolone dimycocerosate esters (PDIMs). Sequence analysis suggested that PapA5, a so-called polyketide-associated protein (Pap) encoded in the PDIM synthesis gene cluster, as well as PapA5 homologs found in Mt and other species, are a subfamily of acyltransferases. Studies with recombinant protein confirmed that PapA5 is an acetyltransferase. Deletion analysis in Mt demonstrated that papA5 is required for PDIM synthesis. We propose that PapA5 catalyzes diesterification of phthiocerol and phthiodiolone with mycocerosate. These studies present the functional characterization of a Pap and permit inferences regarding roles of other Paps in the synthesis of complex lipids, including the antibiotic rifamycin

show abstract

Section: Discussionmentioning

confidence: 53%

“…Both motifs are present in ATs (32,33). By analogy with CAT, a prototype AT, H124 of PapA5 would be expected to act as the catalytic base (41). By the same criterion, D128 in PapA5 should be required as an active site stabilizer (38,42 (38,41).…”

Section: Discussionmentioning

confidence: 99%

Mycobacterial polyketide-associated proteins are acyltransferases: Proof of principle with Mycobacterium tuberculosis PapA5

Onwueme

Ferreras

Buglino

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…As mentioned before, CATs possess the highly conserved HHxxxDG sequence, in which histidine and aspartate have been identified as crucial active-site residues (61,180,181). His195 (of CAT III ) acts as a general base and deprotonates the C3 hydroxyl of chloramphenicol, which in turn attacks the carbonyl carbon atom of the thioester bond in acetyl-CoA (as described for AtfA [Fig.…”

Section: Chloramphenicol Acetyltransferasementioning

confidence: 99%

Acyltransferases in Bacteria

Röttig

Steinbüchel

2013

Microbiol Mol Biol Rev

148

141

View full text Add to dashboard Cite

SUMMARY Long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. They build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. Acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compounds. Lipases represent another important enzyme class dealing with fatty acyl chains; however, they cannot be regarded as acyltransferases in the strict sense. This review provides a detailed survey of the wide spectrum of bacterial acyltransferases and compares different enzyme families in regard to their catalytic mechanisms. On the basis of their studied or assumed mechanisms, most of the acyl-transferring enzymes can be divided into two groups. The majority of enzymes discussed in this review employ a conserved acyltransferase motif with an invariant histidine residue, followed by an acidic amino acid residue, and their catalytic mechanism is characterized by a noncovalent transition state. In contrast to that, lipases rely on completely different mechanism which employs a catalytic triad and functions via the formation of covalent intermediates. This is, for example, similar to the mechanism which has been suggested for polyester synthases. Consequently, although the presented enzyme types neither share homology nor have a common three-dimensional structure, and although they deal with greatly varying molecule structures, this variety is not reflected in their mechanisms, all of which rely on a catalytically active histidine residue.

show abstract

“…As with VatD, alanine substitution of essential catalytic histidyl residues that facilitate transfer of acyl groups in other enzymes, including chloramphenicol acetyltransferase (30) and the serine protease subtilisin (31), results in a 10 5 -to 10 6 -fold reduction in catalytic competence. In the former case, His-195 acts as a general base to activate a hydroxy group of chloramphenicol for direct nucleophilic attack on the carbonyl group of AcCoA (32).…”

Section: Structure Of Vatd-dalfopristin Complexmentioning

confidence: 99%

Structural Basis of Synercid® (Quinupristin-Dalfopristin) Resistance in Gram-positive Bacterial Pathogens

Kehoe

Snidwongse

Courvalin

et al. 2003

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Synercid®, a new semisynthetic streptogramin-derived antibiotic containing dalfopristin and quinupristin, is used in treatment of life-threatening infections caused by glycopeptide-resistant Enterococcus faecium and other bacterial pathogens. However, dissemination of genes encoding virginiamycin acetyltransferases, enzymes that confer resistance to streptogramins, threatens to limit the medical utility of the quinupristin-dalfopristin combination. Here we present structures of virginiamycin acetyltransferase D (VatD) determined at 1.8 Å resolution in the absence of ligands, at 2.8 Å resolution bound to dalfopristin, and at 3.0 Å resolution in the presence of acetyl-coenzyme A. Dalfopristin is bound by VatD in a similar conformation to that described previously for the streptogramin virginiamycin M1. However, specific interactions with the substrate are altered as a consequence of a conformational change in the pyrollidine ring that is propagated to adjacent constituents of the dalfopristin macrocycle. Inactivation of dalfopristin involves acetyl transfer from acetylcoenzyme A to the sole (O-18) hydroxy group of the antibiotic that lies close to the side chain of the strictly conserved residue, His-82. Replacement of residue 82 by alanine is accompanied by a fall in specific activity of >10 5 -fold, indicating that the imidazole moiety of His-82 is a major determinant of catalytic rate enhancement by VatD. The structure of the VatD-dalfopristin complex can be used to predict positions where further structural modification of the drug might preclude enzyme binding and thereby circumvent Synercid® resistance.

show abstract

Replacement of catalytic histidine-195 of chloramphenicol acetyltransferase: Evidence for a general base role for glutamate

Cited by 72 publications

References 28 publications

Mycobacterial polyketide-associated proteins are acyltransferases: Proof of principle with Mycobacterium tuberculosis PapA5

Mycobacterial polyketide-associated proteins are acyltransferases: Proof of principle with Mycobacterium tuberculosis PapA5

Acyltransferases in Bacteria

Structural Basis of Synercid® (Quinupristin-Dalfopristin) Resistance in Gram-positive Bacterial Pathogens

Contact Info

Product

Resources

About