Protein profiles of 936-related phages as determined by SDS–15% PAGE. The gel was stained with Coomassie blue. Lane 1, phage p2; lane 2, Q7; lane 3, Q11; lane 4, Q42; lane 5, Q46; lane M, prestained molecular mass markers (New England Biolabs). Arrow, major structural protein used for N-terminal sequencing and encoded by the msp gene.