Molecular basis of dimerization of lytic transglycosylase revealed by the crystal structure of MltA from Acinetobacter baumannii

Peptidoglycan digestion by murein-degrading enzymes is a critical process in bacterial cell growth and/or cell division. The membrane-bound lytic murein transglycosylase A (MltA) is a murein-degrading enzyme; it catalyzes the cleavage of the β-1,4-glycosidic linkage between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycans. Although substrate recognition and cleavage by MltA have been examined by previous structural and mutagenesis studies, the overall mechanism of MltA in conjunction with other functionally related molecules on the outer membrane of bacterial cells for peptidoglycan degradation has remained elusive. In this study, the crystal structure of MltA from the virulent human pathogen Acinetobacter baumannii is characterized and presented. The study indicated that MltA from A. baumannii forms homodimers via an extra domain which is specific to this species. Furthermore, the working mechanism of MltA with various functionally related proteins on the bacterial outer membrane was modeled based on the structural and biochemical analysis.

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High-Resolution Crystal Structure of MltE, an Outer Membrane-Anchored Endolytic Peptidoglycan Lytic Transglycosylase fromEscherichia coli

Biochemistry ◽

10.1021/bi200085y ◽

2011 ◽

Vol 50 (13) ◽

pp. 2384-2386 ◽

Cited By ~ 35

Author(s):

Cecilia Artola-Recolons ◽

César Carrasco-López ◽

Leticia I. Llarrull ◽

Malika Kumarasiri ◽

Elena Lastochkin ◽

...

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Outer Membrane ◽

Fromescherichia Coli ◽

Lytic Transglycosylase

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Holarrhena antidysenterica as a resistance modifying agent against Acinetobacter baumannii: Its effects on bacterial outer membrane permeability and efflux pumps

Microbiological Research ◽

10.1016/j.micres.2013.09.004 ◽

2014 ◽

Vol 169 (5-6) ◽

pp. 417-424 ◽

Cited By ~ 17

Author(s):

Sasitorn Chusri ◽

Pinanong Na-Phatthalung ◽

Thanyaluck Siriyong ◽

Supakit Paosen ◽

Supayang P. Voravuthikunchai

Keyword(s):

Acinetobacter Baumannii ◽

Membrane Permeability ◽

Outer Membrane ◽

Efflux Pumps ◽

Modifying Agent ◽

Holarrhena Antidysenterica ◽

Bacterial Outer Membrane ◽

Outer Membrane Permeability ◽

Resistance Modifying Agent

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High-resolution crystal structure of an outer membrane-anchored endolytic peptidoglycan lytic transglycosylase (MltE) fromEscherichia coli

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767311087976 ◽

2011 ◽

Vol 67 (a1) ◽

pp. C476-C476

Author(s):

C. Artola-Recolons ◽

C. Carrasco-López ◽

L. I. Llarrull ◽

M. Kumarasiri ◽

E. Lastochkin ◽

...

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Outer Membrane ◽

Fromescherichia Coli ◽

Lytic Transglycosylase

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Binding of mutagenic pyrolyzates to fractions of intestinal bacterial cells

Canadian Journal of Microbiology ◽

10.1139/m92-101 ◽

1992 ◽

Vol 38 (7) ◽

pp. 614-617 ◽

Cited By ~ 9

Author(s):

Xue Bin Zhang ◽

Yoshiyuki Ohta

Keyword(s):

Escherichia Coli ◽

Cell Wall ◽

Outer Membrane ◽

Bacterial Strain ◽

Cytoplasmic Membrane ◽

Intestinal Bacteria ◽

Bacterial Cells ◽

Gram Negative ◽

Membrane Bound ◽

Cell Fractions

The binding of mutagenic pyrolyzates to cell fractions from some gram-negative intestinal bacteria and to thermally treated bacterial cells was investigated. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) were effectively bound by several of the bacterial cells. The cell wall skeletons of all bacteria effectively bound Trp-P-1 and Trp-P-2. Their cytoplasmic fractions retained Trp-P-1 and Trp-P-2, but to a lesser extent than the cell wall skeletons. 2-Amino-3-methylimidazo [4,5-f]quinoline (IQ) was not found in their cytoplasmic fractions. These cell wall skeletons also bound 2-amino-6-methyldipyrido[1,2-a:3′2′-d] imidazole (Glu-P-1), 2-amino-5-phenylpyridine (Phe-P-1), IQ, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX). The amount of each mutagen bound differed with the type of mutagen and the bacterial strain used. The outer membrane of Escherichia coli IFO 14249 showed binding of about 123.7 μg/mg of Trp-P-2, and its cytoplasmic membrane bound 57.14 μg/mg. Trp-P-2 bound to the bacterial cells was extracted with ammonia (5%), methanol, and ethanol but not with water. Key words: cell wall skeletons, outer membrane, cytoplasmic membrane, binding of mutagenic pyrolyzates.

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