Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/127087
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Amph, a bifunctional DD-endopeptidase and DD-carboxypeptidase of Escherichia coli |
Autor: | González-Leiza, Silvia M.; Pedro, Miguel Ángel de CSIC; Ayala, Juan Alfonso CSIC ORCID | Fecha de publicación: | dic-2011 | Editor: | American Society for Microbiology | Citación: | Journal of Bacteriology 193: 6887- 6894 (2011) | Resumen: | In Escherichia coli, low-molecular-mass penicillin-binding proteins (LMM PBPs) are important for correct cell morphogenesis. These enzymes display DD-carboxypeptidase and/or DD-endopeptidase activities associated with maturation and remodeling of peptidoglycan (PG). AmpH has been classified as an AmpH-type class C LMM PBP, a group closely related to AmpC β-lactamases. AmpH has been associated with PG recycling, although its enzymatic activity remained uncharacterized until now. Construction and purification of Histagged AmpH from E. coli permitted a detailed study of its enzymatic properties. The N-terminal export signal of AmpH is processed, but the protein remains membrane associated. The PBP nature of AmpH was demonstrated by its ability to bind the β-lactams Bocillin FL (a fluorescent penicillin) and cefmetazole. In vitro assays with AmpH and specific muropeptides demonstrated that AmpH is a bifunctional DD-endopeptidase and DD-carboxypeptidase. Indeed, the enzyme cleaved the cross-linked dimers tetrapentapeptide (D45) and tetratetrapeptide (D44) with efficiencies (k cat/K m) of 1,200 M -1 s -1 and 670 M -1 s -1, respectively, and removed the terminal D-alanine from muropeptides with a C-terminal D-Ala-D-Ala dipeptide. Both DD-peptidase activities were inhibited by 40 μM cefmetazole. AmpH also displayed a weak β-lactamase activity for nitrocefin of 1.4 × 10 -3 nmol/μg protein/min, 1/1,000 the rate obtained for AmpC under the same conditions. AmpH was also active on purified sacculi, exhibiting the bifunctional character that was seen with pure muropeptides. The wide substrate spectrum of the DD-peptidase activities associated with AmpH supports a role for this protein in PG remodeling or recycling. © 2011, American Society for Microbiology. | URI: | http://hdl.handle.net/10261/127087 | DOI: | 10.1128/JB.05764-11 | Identificadores: | doi: 10.1128/JB.05764-11 issn: 0021-9193 |
Aparece en las colecciones: | (CBM) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
Ayala Juan A AmpH.pdf | 630,97 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
PubMed Central
Citations
25
checked on 12-abr-2024
SCOPUSTM
Citations
46
checked on 11-abr-2024
WEB OF SCIENCETM
Citations
44
checked on 27-feb-2024
Page view(s)
465
checked on 19-abr-2024
Download(s)
250
checked on 19-abr-2024
Google ScholarTM
Check
Altmetric
Altmetric
Artículos relacionados:
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.