Crystallization and 7 A resolution electron density map of the large fragment of Escherichia coli DNA polymerase I

Crystals of the large fragment of Escherichia coli DNA polymerase I have been grown that diffract to better than 2.8 A resolution. They are in tetragonal space group P4(3) with a = b = 104.1 A, c = 86 A. A 7 A resolution map shows the protein to consist of two domains and to be mostly alpha-helical. The active site has been located by binding nucleoside monophosphates.