Reinigung, Eigenschaften und Substratspezifität einer N-Acetylglucosaminidase aus E. coli B

Maass, D.; Pelzer, H.; Weidel, Wolfhard

doi:10.1515/znb-1964-0511

Cited by 12 publications

(8 citation statements)

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“…2) was initially identified in a cell extract from E. coli (198). Using monomer and dimer muropeptides or p-nitrophenyl-␤-N-acetylglucosaminide as a substrate, it was purified as a cytoplasmic enzyme (155,310). An activity-deficient mutant showed normal growth and morphology (311).…”

Section: N-acetylglucosaminidasementioning

confidence: 99%

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Peptidoglycan Hydrolases of Escherichia coli

Heijenoort

2011

Microbiol Mol Biol Rev

189

233

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SUMMARY The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway.

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Section: N-acetylglucosaminidasementioning

confidence: 99%

“…However, it is required for the PG recycling process (196). NagZ is specific for the ␤ linkage and is active on monomer and dimer muropeptides (155, 310) but not on the tetrasaccharide muropeptide (155). It cleaves the GlcNAc-(134)-1,6-anhydro-MurNAc disaccharide (271).…”

Section: N-acetylglucosaminidasementioning

confidence: 99%

Peptidoglycan Hydrolases of Escherichia coli

Heijenoort

2011

Microbiol Mol Biol Rev

189

233

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“…1). The murein completely encloses the cell, thereby forming a kind of bag-shaped exoskeleton called a sacculus (Weidel & Pelzer, 1964;Mirelman, 1979;Tipper & Wright, 1979;Rogers et al, 1980). Expansion of the wall during bacterial growth and splitting of the septum for cell separation call for enzymes that cleave covalent bonds within the murein sacculus.…”

Section: Introductionmentioning

confidence: 99%

“…New insight gained over the past decade has led to an emerging picture of a rather dynamic state of the bacterial sacculus in which the murein net is continuously subjected to intense hydrolytic attack, as indicated by insertion of new material, and remodelling and release of aged material. In addition to acting as pacemaker and spacemaker enzymes for cell wall growth (Weidel & Pelzer, 1964;Tomasz, 1983Tomasz, , 1984 some of the murein hydrolases can act as autolysins, thereby representing potential suicide enzymes.…”

Section: Introductionmentioning

confidence: 99%

The murein hydrolases of Escherichia coli: properties, functions and impact on the course of infections in vivo

Höltje

Tuomanen

1991

Journal of General Microbiology

155

133

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“…coli [3,4]. This enzyme system comprises lysozyme, an N-acetylglucosaminidase [5], a transglycosidase [6,7], a muramyl-amidase [3,8], several endopeptidases [9] and a t least two carboxy-peptidases [4, lo]. The activity of a t least some hydrolases is subject to both temporal and spatial regulation; in the cellular life-cycle localized hydrolase action [ l l ] is triggered at a given stage of cell division [12].…”

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confidence: 99%

Murein Hydrolases in the Envelope of Escherichia coli

Hartmann

Bock-Hennig²,

Schwarz

1974

European Journal of Biochemistry

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Properties of murein hydrolases, assumed to play an essential role in bacterial morphogenesis, are described. Evidence is presented that in the intact cell these enzymes are prevented from uncontrolled reaction. It is shown that the "barrier" between the enzymes and their substrate sacculus, a shape-maintaining macromolecule within the cell envelope, can be artificially broken. Assay systems to measure murein hydrolase activity in the intact cell, in isolated cell envelopes and after solubilization are described. A combination of Triton X-100 and sodium chloride is shown to liberate membrane-bound hydrolases effectively.Growth and division of a bacterial cell occur in concert with controlled modification of the cell shape. This modification involves variation of the sacculus, a shape-maintaining macromolecule which is integrated into the complex cell envelope. The sacculus consists of murein, a net-like polymer in which polysaccharide chains are intertied by short peptide bridges. I n the case of Escherichia coli these peptide bridges contain 2,6-diaminopimelic acid as an essential component (for a review see [l]). The closed murein net which completely surrounds the cell can be modified only if some of the existent covalent bonds are initially split (for a review see [ Z ] ) . This splitting has to be done by enzymes, murein hydrolases, which thus are directly involved in bacterial morphogenesis.A set of different types of murein hydrolases is found in E . coli [3,4]. This enzyme system comprises lysozyme, an N-acetylglucosaminidase [5], a transglycosidase [6,7], a muramyl-amidase [3,8], several endopeptidases [9] and a t least two carboxy-peptidases [4, lo]. The activity of a t least some hydrolases is subject to both temporal and spatial regulation; in the cellular life-cycle localized hydrolase action [ l l ] is triggered at a given stage of cell division [12]. The spatial and temporal control of hydrolase action might be correlated with the fact that most, if not all, murein hydrolases in E . coli are membrane- Eur. J. Biochem. 41 (1974) bound and thus in close contact with their substrate murein. This fact will be considered in more detail in the discussion of this paper.A study of the mechanisms by which temporal and spatial control of enzyme action is accomplished, has to start with an analysis of the properties of the complex murein hydrolase system and of its components. This paper deals with the measurement of overall murein hydrolase activity in intact cells and in isolated cell envelopes. Evidence will be presented suggesting the existence of a "barrier" between hydrolases and their substrate murein ; we speculate that it is involved in the regulation of enzyme action. I n addition, methods €or solubilization of murein hydrolases from the envelope, mentioned previously [6], are given in more detail. I n a forthcoming paper the purification and characteristics of one of the membrane-bound hydrolases, a penicillinsensitive endopeptidase, will be described. MATERIALS AND METHODS Strain, Culture Con...

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Reinigung, Eigenschaften und Substratspezifität einer N-Acetylglucosaminidase aus E. coli B

Abstract: Purification and characterization of a β-N-acetyl-glucosaminidase from E. coli B are described. The enzyme appears to possess a peculiarly narrow specificity, as indicated by studies employing for substrates various coli cell wall mucopeptides.

Cited by 12 publications

References 0 publications

Peptidoglycan Hydrolases of Escherichia coli

Peptidoglycan Hydrolases of Escherichia coli

The murein hydrolases of Escherichia coli: properties, functions and impact on the course of infections in vivo

Murein Hydrolases in the Envelope of Escherichia coli

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