Abstract
Endonuclease from Serratia marcescens hydrolyzes internucleotide phosphorothioate linkages of R P configuration with inversion of configuration at P-atom. This observation supports a reported architecture of the active site, with 3′-bridging and pro-S P non-bridging oxygen atoms of the scissile phosphate group involved in direct contact with hydrated magnesium cation, while His-89 activates a water molecule which attacks the phosphorus atom according to a one-step in-line mechanism. The presence of a phosphorothioate bond of S P configuration downstream to that one being cleaved reduces the rate of hydrolysis. This suggests participation of the pro-S P oxygen atom of that phosphate bond in the mechanism of action of the enzyme, which was not detected in published crystallographic analyses.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
