title: Studies on Escherichia coli chromosome proteins. I. Analysis of the proteins by two-dimensional gel electrophoresis.
abstract: As an approach for studying the function of chromosome proteins in DNA replication and gene expression, proteins remaining attached to Escherichia coli nucleoids were analyzed by two-dimensional polyacrylamide slab gel electrophoresis. Nucleoids were isolated by gentle lysis of the cells in the presence of a DNA counter-ion such as 1 M NaCl or 5 mM spermidine. In exponentially growing cells, about 100 proteins have been found to exist in the nucleoids. Kinetic studies indicated that the number of chromosome proteins remaining attached varied with time after synchronization. Based on the pattern of the variation, appearance, increase or disappearance of the 29 major proteins, nucleoid proteins were shown to be classified in six different groups (groups A--F). A strong correlation was observed between the variation of proteins belonging to group D and initiation of DNA synthesis or cell division.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D002876:Chromosomes, Bacterial / Q000032:analysis*; D004261:DNA Replication; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004926:Escherichia coli / Q000032:analysis*; D008970:Molecular Weight; D009698:Nucleoproteins / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D009698:Nucleoproteins