A New SHV-Derived Extended-Spectrum β-Lactamase (SHV-24) That Hydrolyzes Ceftazidime through a Single-Amino-Acid Substitution (D179G) in the Ω-Loop

ABSTRACT A new SHV-derived extended-spectrum β-lactamase (SHV-24) conferring high-level resistance to ceftazidime but not cefotaxime and cefazolin was identified in Japan. This enzyme was encoded by a transferable 150-kb plasmid from an Escherichia coliclinical isolate. The pI and Km for CAZ of this enzyme were 7.5 and 30 μM, respectively. SHV-24 was found to have a D179G substitution in the Ω-loop of the enzyme.

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Capnocytophaga ochracea: Characterization of a Plasmid-Encoded Extended-Spectrum TEM-17 β-Lactamase in the Phylum Flavobacter-Bacteroides

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.3.760-762.2000 ◽

2000 ◽

Vol 44 (3) ◽

pp. 760-762 ◽

Cited By ~ 21

Author(s):

Agnes Rosenau ◽

Blandine Cattier ◽

Nathalie Gousset ◽

Patrick Harriau ◽

Alain Philippon ◽

...

Keyword(s):

Amino Acid ◽

Clinical Isolate ◽

Amino Acid Substitution ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Extended Spectrum

ABSTRACT A plasmid-encoded extended-spectrum TEM β-lactamase with a pI of 5.5 was detected in a Capnocytophaga ochracea clinical isolate. The bla gene was associated with a strong TEM-2 promoter and was derived from bla TEM-1a with a single-amino-acid substitution: Glu104→Lys, previously assigned to TEM-17, which is thus the first TEM β-lactamase to be reported in the phylum Flavobacter-Bacteroides.

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A single amino acid substitution in the A subunit of Escherichia coli enterotoxin results in a loss of its toxic activity.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)45736-5 ◽

1990 ◽

Vol 265 (36) ◽

pp. 22520-22525

Author(s):

T Tsuji ◽

T Inoue ◽

A Miyama ◽

K Okamoto ◽

T Honda ◽

...

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Amino Acid Substitution ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Toxic Activity ◽

A Subunit

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A single amino acid substitution in aromatic hydroxylase (HpaB) of Escherichia coli alters substrate specificity of the structural isomers of hydroxyphenylacetate

BMC Microbiology ◽

10.1186/s12866-020-01798-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Hanseol Kim ◽

Sinyeon Kim ◽

Dohyeon Kim ◽

Sung Ho Yoon

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Substrate Specificity ◽

Amino Acid Substitution ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Structural Isomers

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TEM-89 β-Lactamase Produced by a Proteus mirabilis Clinical Isolate: New Complex Mutant (CMT 3) with Mutations in both TEM-59 (IRT-17) and TEM-3

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.12.3591-3594.2001 ◽

2001 ◽

Vol 45 (12) ◽

pp. 3591-3594 ◽

Cited By ~ 20

Author(s):

Catherine Neuwirth ◽

Stephanie Madec ◽

Eliane Siebor ◽

Andre Pechinot ◽

Jean-Marie Duez ◽

...

Keyword(s):

Amino Acid ◽

Clinical Isolate ◽

Amino Acid Substitution ◽

Proteus Mirabilis ◽

Hydrolytic Activity ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Clinical Strain ◽

Almost All

ABSTRACT TEM-89 (CMT-3) is the first complex mutant β-lactamase produced by a clinical strain of Proteus mirabilis (strain Pm 631). This new enzyme, which has a pI of 6.28, is derived from TEM-3 and has a single amino acid substitution also encountered in TEM-59 (inhibitor-resistant TEM β-lactamase IRT-17): Ser-130 to Gly. TEM-89 hydrolyzed penicillins to the same extent that TEM-3 did but lost almost all hydrolytic activity for cephalosporins and, like TEM-59, was highly resistant to inhibitors.

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A Single Amino Acid Substitution in the Active Site of Escherichia coli Aspartate Transcarbamoylase Prevents the Allosteric Transition

Journal of Molecular Biology ◽

10.1016/j.jmb.2005.03.073 ◽

2005 ◽

Vol 349 (2) ◽

pp. 413-423 ◽

Cited By ~ 6

Author(s):

Kimberly A. Stieglitz ◽

Styliani C. Pastra-Landis ◽

Jiarong Xia ◽

Hiro Tsuruta ◽

Evan R. Kantrowitz

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Amino Acid Substitution ◽

Active Site ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Aspartate Transcarbamoylase ◽

Allosteric Transition

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A single amino acid substitution in the enzymatic domain of cytotoxic necrotizing factor type 1 of Escherichia coli alters the tissue culture phenotype to that of the dermonecrotic toxin of Bordetella spp.

Molecular Microbiology ◽

10.1111/j.1365-2958.2006.05157.x ◽

2006 ◽

Vol 60 (4) ◽

pp. 939-950 ◽

Cited By ~ 8

Author(s):

Beth A. McNichol ◽

Susan B. Rasmussen ◽

Karen C. Meysick ◽

Alison D. O'Brien

Keyword(s):

Escherichia Coli ◽

Tissue Culture ◽

Amino Acid ◽

Amino Acid Substitution ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Cytotoxic Necrotizing Factor ◽

Dermonecrotic Toxin ◽

Factor Type

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A Single Amino Acid Substitution in a Mannosyltransferase, WbdA, Converts the Escherichia coli O9 Polysaccharide into O9a: Generation of a New O-Serotype Group

Journal of Bacteriology ◽

10.1128/jb.182.9.2567-2573.2000 ◽

2000 ◽

Vol 182 (9) ◽

pp. 2567-2573 ◽

Cited By ~ 30

Author(s):

Nobuo Kido ◽

Hidemitsu Kobayashi

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Amino Acid Substitution ◽

Site Directed Mutagenesis ◽

Single Amino Acid Substitution ◽

Single Amino Acid ◽

Directed Mutagenesis ◽

E Coli ◽

Chimeric Genes ◽

Functional Studies

ABSTRACT wbdA is a mannosyltransferase gene that is involved in synthesis of the Escherichia coli O9a polysaccharide, a mannose homopolymer with a repeating unit of 2-αMan-1,2-αMan-1,3-αMan-1,3-αMan-1. The equivalent structural O polysaccharide in the E. coli O9 andKlebsiella O3 strains is 2-αMan-1,2-αMan-1,2-αMan-1,3-αMan-1,3-αMan-1, with an excess of one mannose in the 1,2 linkage. We have cloned wbdAgenes from these O9 and O3 strains and shown by genetic and functional studies that wbdA is the only gene determining the O-polysaccharide structure of O9 or O9a. Based on functional analysis of chimeric genes and site-directed mutagenesis, we showed that a single amino acid substitution, C55R, in WbdA of E. coli O9 converts the O9 polysaccharide into O9a. DNA sequencing revealed the substitution to be conserved in other E. coli O9a strains. The reverse substitution, R55C, in WbdA of E. coli O9a resulted in lipopolysaccharide synthesis showing no ladder profile instead of the conversion of O9a to O9. This suggests that more than one amino acid substitution in WbdA is required for conversion from O9a to O9.

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