REGION-SPECIFIC RECOMBINATION IN PHAGE T4. II. STRUCTURE OF THE RECOMBINANTS

Jack N. Levy ¹ and Edward B. Goldberg ¹

¹ Tufts University School of Medicine, Department of Molecular Biology and Microbiology, 136 Harrison Avenue, Boston, Massachusetts 02111

In this paper, we present results of crosses designed to elucidate the structure of recombinants in the tail-fiber region of bacteriophage T4, in which a glucosylation-dependent recombination mechanism is operative, and the cause of this "special" recombination in glucosylated crosses is discussed. We present evidence that, when phage are nonglucosylated, recombination in the tail-fiber region proceeds via long heteroduplex overlaps. Mismatched bases within such regions (in nonglucosylated phage) are repaired efficiently (as contrasted to those of glucosylated phage), but asymmetrically; that is, there may not be an equal probability of resolving the mismatch to mutant or wild type.