My Life with Bacteriophage φ29

This article is a survey of my scientific work over 52 years. During my postdoctoral stay in Severo Ochoa's laboratory, I determined the direction of reading of the genetic message, and I discovered two proteins that I showed to be involved in the initiation of protein synthesis. The work I have done in Spain with bacteriophage phi 29 for 45 years has been very rewarding. I can say that I was lucky because I did not expect that phi 29 would give so many interesting results, but I worked hard, with a lot of dedication and enthusiasm, and I was there when the luck arrived. I would like to emphasize our work on the control of phi 29 DNA transcription and, in particular, the finding for the first time of a protein covalently linked to the 5'- ends of phi 29 DNA that we later showed to be the primer for the initiation of phage DNA replication. Very relevant was the discovery of the phi 29 DNA polymerase, with its properties of extremely high processivity and strand displacement capacity, together with its high fidelity. The phi 29 DNA polymerase has become an ideal enzyme for DNA amplification, both rolling- circle and whole- genome linear amplification. I am also very proud of the many brilliant students and collaborators with whom I have worked over the years and who have become excellent scientists. This Reflections article is not intended to be the end ofmy scientific career. I expect to work for many years to come.