Publications

poly 2'-o-ethylcytidylate, an inhibitor and poor template for amv reverse transcriptase.	poly(2'-o-ethylcytidylate) is a poor template-primer for purified avian myeloblastosis virus reverse transcriptase; the relative activities of the template-primers poly(c)-oligo(dg), poly(cm)-oligo(dg) and poly(ce)-oligo(dg) are 23:16:1. a mixture of poly(ce) and poly(di) is inactive as template-primer, in agreement with the observed inability of these to form a helical complex. by contrast the inactivity of poly(ce)-poly(i) is shown to be due to the influence of the 2'-o-ethyl residue. poly(ce) ...	1976	60742
on the association of reverse transcriptase with polynucleotide templates during catalysis.	the association of avian myeloblastosis virus (amv) dna polymerase with polynucleotide templates during catalysis has been studied. during the course of polymerization, different template-primer complexes were added and the ability of the enzyme to switch from one polynucleotide template to another was determined. at 37 degrees c as well as at 4 degrees c, the polymerase is able to switch from certain template-primer complexes to others. for example, the addition of poly(a)-oligo(dt) during the ...	1976	60129
stepwise dissociation of high molecular weight avian myeloblastosis virus rna: 30-40s rna subunits--the best natural template-primer for viral reverse transcriptase.	controlled disruption of 60s amv rna with formamide was used to prepare 50-55s and 30-40s rnas. when the activities of these rnas as templates for amv reverse transcriptase were compared it was found that 50-55s rna was 1-5 times and 30-40s rna 2 to 3 times more active than 60s rna. the 30-40s rna produced by heating, instead of formamide disruption, was inactive as a template but activity was restored by addition of oligo(dt). 40% of the 4s rna initially associated with the 60s rna remained ass ...	1976	59791
mechanism of release of active alpha subunit from dimeric alpha beta avian myeloblastosis virus dna polymerase.	storage of the dimeric (alphabeta) form of avian myeloblastosis virus (amv) dna polymerase in glycerol resulted in the release of the smaller alpha subunit, as detected by glycerol gradient sedimentation. analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of enzyme stored in glycerol showed the concomitant appearance of several polypeptides and a lowering in the level of both beta and alpha components. this reduction appears to be the result of cleavages introduced by traces o ...	1976	58080
evidence for circularization of the avian oncornavirus rna genome during proviral dna synthesis from studies of reverse transcription in vitro.	the rna-directed dna polymerase (deoxynucleosidetriphosphate:dna deoxynucleotidyltransferase ec 2.7.7.7) of avian oncornavirus requires a tryptophan trna (trnatrp) primer molecule located close to the 5' end of the viral rna genome for the initiation of dna synthesis in vitro. in this communication we demonstrate that the dna product, transcribed from avian myeloblastosis virus (amv) 35s rna containing only trnatrp as primer, is located also at the 5' end of the rna genome. more importantly, we ...	1976	57620
mechanism of interaction of avian myeloblastosis virus reverse transcriptase with avian myeloblastosis virus rna.	the synthesis of dna on avian myeloblastosis virus (amv) rna as the primer-template using amv reverse transcriptase in vitro has been examined as a function of the concentrations of these components, as well as a function of the ionic strenth of the assay medium. the results are consistent with the hypothesis that two types of sites exist on the amv rna: inactive "dead-end" sites that merely bind the enzyme, and active binding sites that lead to dna synthesis. velocity sedimentation studies of r ...	1976	56463
sequences related to the rna tumor viruses in the rna and dna of human leukemias and lymphomas.	dna-rna hybridization was used to explore whether human neoplasias contain rna molecules having sequence homologies to those of the rna tumor viruses known to cause similar diseases in animals. the pattern of specific rnas found in the human tumors showed a remarkable concordance with the predictions deducible from the animal systems. thus human breast cancer contains rna homologous only to that of the murine mammary tumor virus (mmtv). human leukemias, sarcomas, and lymphomas (including hodgkin ...	1975	51626
properties of oncornavirus rna-directed dna polymerase, the rna template, and the intracellular products formed early during infection and cell transformation.	we have investigated three aspects of rna turmor virus replication and cell transformation: (1) the properties of the purified avian and mammalian viral rna-directed dna polumerase, (2) some characteristics of the viral 60-70s rna genome, 30-40s rna subunits and intracellular viral rna species, and (3) the interaction of the viral dna polymerase with its rna template early during infection and cell transformation by the murine sarcoma-leukemia virus (msv[mlv]). avian myeloblastosis virus (amv) c ...	1975	50902
studies on reverse transcriptase of rna tumor viruses iii. properties of purified moloney murine leukemia virus dna polymerase and associated rnase h.	dna polymerase was purified from a cloned isolate of moloney murine leukemia virus (m-mulv). purified m-mulv dna polymerase, upon analysis by polyacrylamide gel electrophoresis, showed one major polypeptide of mol wt 80,000. estimation of molecular weight from the sedimentation rate of the purifed enzyme in a glycerol gradient was consistent with a structure containing one polypeptide. m-mulv dna polymerase could transcribe ribopolymers, deoxyribopolymers, and heteropolymers as efficiently as di ...	1975	46925
properties of solubilized rna-dependent rna polymerase from alfalfa mosaic virus-infected and healthy tobacco plants.		1978	33485
transmission of alfalfa mosaic virus through nicandra physaloides seeds and its localization in embryo cotyledons.	alfalfa mosaic virus (amv) was found to be transmitted through seeds of nicandra physaloids l. the average seed transmission rate of the amv isolates t6, lmbg-4 and st amounted to 23, 4 and 0 per cent, repectively. in the cytoplasm of parenchyma cells of embryo cotyledons of seeds from plants infected with the t6 isolate, electron microscopy revealed amv aggregates of type 2a and aggregations of irregularly viral particles with a tendency to subparallel alignment, representing early stages of ty ...	1977	20770
alfalfa mosaic virus protein polymerization.		1977	18611
a study of the states of aggregation of alfalfa mosaic virus protein.	the states of aggregation of alfalfa mosaic virus (amv) protein have been characterized by sedimentation velocity experiments and electron microscopy. the main association product is a spherical particle with an s value of about 30s. it is highly likely that the assembly of this particle starts with dimers of the 25000 molecular mass unit resulting in an icosahedral particle made of 30 dimers. no intermediate aggregation products have been detected. the clustering pattern of the protein in the c ...	1976	13424
use of cross-linking in studying the structure of rna tumour viruses.	treatment of intact avian myeloblastosis virus (amv) with dimethyl suberimidate dihydrochloride (dms), a cross-linking agent specific for amino groups, was found to result in progressive cross-linking among viral proteins, as revealed by polyacrylamide gel electrophoresis (page) in the presence of sodium dodecyl sulphate (sds). free viral proteins were not cross-linked. the cross-linked protein complex with an apparent molecular weight of 50,000 daltons was studied in detail.	1976	9823
rna-protein interactions in alfalfa mosaic virus.	particles of the bottom component of alfalfa mosaic virus have a compact bacilliform structure at neutral ph. when the ph is raised to 8.3 the structure unfolds. since the particle weight does not change it is concluded that the protein subunits remain attached to the rna. the particle weight of the spheroidal top component a of the virus is halved when the particles unfold at ph 8.3. this can be explained by the fact that these particles contain two rna molecules of identical size. free rna mol ...	1976	5938