The primase from bacteriophage T4 is a single-stranded DNA-dependent RNA po
lymerase that is one of the seven proteins that constitute the DNA-replicat
ion machinery of bacteriophage T4. In an attempt to crystallize the protein
, a number of variants were generated. One such construct, which includes t
he C-terminal region (residues 196-340), gave four different crystal forms
which diffract in the 3.5-6.0 Angstrom resolution range.