http://www.cnr.it/ontology/cnr/individuo/prodotto/ID11739
Role of a Conserved Active Site Cation-pi Interaction in Escherichia coli Serine Hydroxymethyltransferase. (Articolo in rivista)
- Type
- Label
- Role of a Conserved Active Site Cation-pi Interaction in Escherichia coli Serine Hydroxymethyltransferase. (Articolo in rivista) (literal)
- Anno
- 2009-01-01T00:00:00+01:00 (literal)
- Alternative label
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
- Vivoli M; Angelucci F; Ilari A; Morea V; Angelaccio ; di Salvo ML; Contestabile R. (literal)
- Pagina inizio
- Pagina fine
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
- Rivista
- Note
- PubMe (literal)
- ISI Web of Science (WOS) (literal)
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
- Dipartimento di Scienze Biochimiche and Istituto Pasteur, Fondazione Cenci Bolognetti, Sapienza Universita di Roma, Piazzale Aldo Moro, 5-00185 Roma, Italy
Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Piazzale Aldo Moro, 5-00185 Roma, Italy. (literal)
- Titolo
- Role of a Conserved Active Site Cation-pi Interaction in Escherichia coli Serine Hydroxymethyltransferase. (literal)
- Abstract
- Serine hydroxymethyltransferase is a pyridoxal 50-phosphate-dependent enzyme that catalyzes the
interconversion of serine and glycine using tetrahydropteroylglutamate as the one-carbon carrier. In all
pyridoxal phosphate-dependent enzymes, amino acid substrates are bound and released through a
transaldimination process, in which an internal aldimine and an external aldimine are interconverted via
gem-diamine intermediates. Bioinformatic analyses of serine hydroxymethyltransferase sequences and
structures showed the presence of two highly conserved residues, a tyrosine and an arginine, engaged in a
cation-? interaction. In Escherichia coli serine hydroxymethyltranferase, the hydroxyl group of this
conserved tyrosine (Tyr55) is located in a position compatible with a role as hydrogen exchanger in the
transaldimination reaction. Because of the location of Tyr55 at the active site, the enhancement of its acidic
properties caused by the cation-? interaction with Arg235, and the hydrogen bonds established by its
hydroxyl group, a role of this residue as acid-base catalyst in the transaldimination process was envisaged.
The role played by this cation-? interaction in the E. coli serine hydroxymethyltransferase was investigated
by crystallography and site-directed mutagenesis using Y55F and three R235 mutant forms. The crystal
structure of the Y55F mutant suggests that the presence of Tyr55 is indispensable for a correct positioning
of the cofactor and for the maintenance of the structure of several loops involved in substrate and cofactor
binding. The kinetic properties of all mutant enzymes are profoundly altered. Substrate binding and
rapid kinetic experiments showed that both Y55 and R235 are required for a correct progress of the
transaldimination reaction. (literal)
- Prodotto di
- Autore CNR
Incoming links:
- Prodotto
- Autore CNR di
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi