Oligomeric structure of p21 ras proteins as determined by radiation inactivation.

摘要: Using radiation inactivation we determined that p21 ras proteins exhibit an oligomeric target size when assayed both structurally and functionally. Similar sizes of in ras-transformed cells purified preparations the protein suggested its structure is homo-oligomeric. monomers were destroyed by with same as GTP binding activity, indicating occurrence a tight association allowing energy transfer between monomers. Irradiation presence GTP, dithiothreitol, or EDTA did not change size. Normal (Gly12) transforming (Lys12) forms exhibited similar sizes. The homo-oligomeric suggests do conform to monomeric alpha subunits classical G (alpha beta gamma heterotrimers) establishes similarities other (such Escherichia coli CRP) which acquire active conformation through subunit reorientation upon nucleotide binding.