title: Molecular multiplicity of nuclease TT1 from Thermus thermophilus HB8.
abstract: Purified nuclease TT1 from Thermus thermophilus HB8 has multimolecular weight forms, each of which is composed of three different subunits, alpha (10.8 x 10(4)), beta (7.8 x 10(4)), and gamma (4.1 x 10(4)). The molecular weights of this enzyme were estimated by gel filtration, polyacrylamide gel electrophoresis and equilibrium sedimentation. It was found that most of the enzyme has a molecular weight of about 22 x 10(4) being a monomer having the subunit composition of alpha beta gamma. The remaining part of the enzyme has larger molecular weights and is considered to be size-isomers of alpha beta gamma. The alpha-helical content, 5.5--6.5%, and the beta-structure, about 28%, were estimated from the CD spectrum at 4 degrees C.
mesh_terms: D002942:Circular Dichroism; D004589:Electrophoresis, Disc; D005092:Exonucleases / Q000302:isolation & purification*; D008970:Molecular Weight; D013056:Spectrophotometry, Ultraviolet; D013824:Thermus / Q000201:enzymology*
chemical_list: D005092:Exonucleases; C025422:nuclease TT1