Accession Number : AD0440093


Title :   PHYSICAL STUDIES ON RIBOSOMES FROM PEA SEEDLINGS,


Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF APPLIED BIOLOGY


Personal Author(s) : Bayley,S T


Report Date : 17 Sep 1963


Pagination or Media Count : 16


Abstract : Eighty ribosomes from the buds of pea seedlings, ribosomal aggregates and 60 s, 40 s and 26 s subunits have been examined in the ultracentrifuge and as positively and hegatively-stained preparations in the electron microscope. The subunits appear to dissociate and reaggregate with comparative ease; in particular the 60 s can associate to form particles heavier than 80 s and can dissociate to a 50 s particle, presumably through the loss of a 26 s subunit. Subunits have been stabilized and fractionated on sucrose gradients containing phosphate buffer and 10% formalin; in fact it was found that centrifuging into sucrose containing formalin was a superior method of fixing pea ribosomal preparations generally. The 26 s subunit appears to be an elongated particle, about 210 to 250 Angstroms long by 90 Angstroms across. Two of these lying side-by-side are similar in size to the 40 s subunit, a disk-like particle 210 to 250 Angstroms in diameter and about 80 Angstomrs thick. The 60 s subunit consists of a 40 s particle plus a pair of 26 s particles lying side-by-side, while the whole 80 s ribosome contains an additional 40 s particle, which with the other 40 s probably sandwiches the two 26 s subunits. In wellpreserved pea ribosomes, there is no indication of cleavage furrows between subunits. There is some evidence that in these ribosomes portions of the ribonucleoprotein molecules exist as rods about 50 Angstroms in diameter. (Author)


Descriptors :   *RIBOSOMES , PLANTS(BOTANY) , PROTEINS , NUCLEOPROTEINS , ESCHERICHIA , RIBONUCLEIC ACIDS , BIOCHEMISTRY


Distribution Statement : APPROVED FOR PUBLIC RELEASE