摘要 |
<p>This invention provides methods for the discovery of molecules that target an essential step of bacterial DNA replication - the sealing of DNA strands by NAD+-dependent DNA ligase. Specific structural components of NAD+-dependent DNA ligase that are important for the reaction of DNA ligase with NAD+ and that comprise a putative binding site for the NMN component of NAD+ were identified. The invention also includes recombinant DNA ligase enzymes that are defective in their reaction with NAD+, but active in the ligation of pre-adenylated DNA nicks. An underlying principle of this invention is the use of NAD+-reactive and NAD+-defective ligases to identify molecules that specifically bind to the NAD+-binding site of DNA ligase and thereby interfere with the reaction of DNA ligase with NAD+.</p> |