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Studies on 4S and 5S RNA of HeLa cells

Citation

Hatlen, Loren Endicott (1970) Studies on 4S and 5S RNA of HeLa cells. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/XBGN-YT10. https://resolver.caltech.edu/CaltechTHESIS:08032015-141200820

Abstract

SECTION I

Section I is concerned with a partial sequence analysis conducted on 5S RNA from HeLa cells. Analysis of the oligonucleotide pattern after pancreatic ribonuclease digestion of a highly-purified preparation of 5S RNA gave results which were in general agreement with those published for KB cells, both with respect to the identity and the frequency of the partial sequences. However, the presence of a trinucleotide not found in the KB 5S pattern, together with the reproducibly much lower than expected molar yield of the larger oligonucleotides strongly suggested the occurrence of alternate sequences at various sites in the 5S molecules of human cells. The presence of ppGp and pppGp at the 5'-terminus of HeLa 5S RNA was clearly demonstrated. The implications of this finding with regard to the origin of 5S RNA are discussed.

SECTION II

In Section II the proportion of the HeLa cell genome complementary to tRNA was investigated by using RNA- DNA hybridization. The value for saturation of the HeLa DNA by tRNA was found to be 1.1 x 10-5, which corresponds to about 4900 sites for tRNA per HeLa cell in an exponentially growing culture. Analysis of the nucleotide composition of the hybridized tRNA revealed significant differences from the nucleotide composition of the input tRNA, with the purine to pyrimidine ratio indicating, however, that these differences were not produced by excessive RNase attack of the hybrid. The size of the hybridized tRNA was only moderately smaller than that of the input RNA; the average S value in formaldehyde was 2.7 (corresponding to a length of about 65 nucleotides), suggesting that a relatively small portion near the ends of the hybridized 4S chains had been removed by RNase.

SECTION III

The proportion of the HeLa cell genome complementary to 5S RNA was investigated by using RNA-DNA hybridization. The value for saturation of the HeLa DNA by 5S RNA was found to be 2.3 x 10-5, which corresponds to about 7,000 sites for 5S RNA per HeLa cell in an exponentially growing culture. Analysis of the nucleotide composition of the hybridized 5S RNA revealed no significant difference from the nucleotide composition of the input RNA. At the RNA to DNA input ratio of 1:1000, the average S value in formaldehyde of the hybridized 5S RNA corresponded to a polynucleotide chain about two-thirds the size of the input RNA.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemistry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Attardi, Giuseppe
Thesis Committee:
  • Unknown, Unknown
Defense Date:2 July 1969
Funders:
Funding AgencyGrant Number
U. S. Public Health ServiceUNSPECIFIED
CaltechUNSPECIFIED
Record Number:CaltechTHESIS:08032015-141200820
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:08032015-141200820
DOI:10.7907/XBGN-YT10
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9074
Collection:CaltechTHESIS
Deposited By: Bianca Rios
Deposited On:04 Aug 2015 14:42
Last Modified:21 Dec 2019 04:10

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