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S H Goodgal

Publications and source records attributed to S H Goodgal.

41 records · Page 3Linked to original sources
PubMed1966

On the nature of recombinants formed during transformation in Hemophilus influenzae.

During the process of transformation in Hemophilus influenzae integration of donor DNA, i.e. the formation of recombinant DNA, involves the incorporation of single-stranded DNA. Evidence was obtained from cesium chloride density gradient centrifugation of DNA from donor-recipient complexes that integration was accompanied by the formation of hybrid DNA with a density intermediate with respect to heavy, (2)H, (15)N, donor and light, (1)H, (4)N recipient DNA. On denaturation the position of the heavy donor DNA moved closer to, but not all the way toward, the density position of the original donor DNA. In addition to supporting the idea of single-stranded incorporation, this evidence suggested that the integrated donor DNA was covalently linked to light recipient DNA. The DNA was taken up in the double-stranded form and no detectable amounts of denatured DNA could be found during the transformation process. However, during the process of integration an amount of donor atoms, equivalent to the amount of hybrid DNA formed, appeared in recipient DNA, and indicated that while one strand of DNA was integrated the other was broken down and resynthesized. The density of the hybrid DNA, as well as rebanding of denatured hybrid, indicated that the size of the integrated piece of DNA was large, approximately 6 x 10(6) daltons.

Centrifugation, Density Gradient↗
PubMed1965

Loss of activity of transforming deoxyribonucleic acid after uptake by Haemophilus influenzae.

Voll, Mary Jane (University of Pennsylvania, Philadelphia), and Sol H. Goodgal. Loss of activity of transforming deoxyribonucleic acid after uptake by Haemophilus influenzae. J. Bacteriol. 90:873-883. 1965.-Transforming deoxyribonucleic acid (DNA) which has been irreversibly removed from solution by competent cells undergoes a progressive loss in marker activity when tested by lysis of the cells and exposure to new recipient cells. The loss of activity is limited and marker-specific, with greater inactivation of those markers with lower efficiencies of transformation. Recipient factors or donor factors which have undergone recombination, as measured by the appearance of linked markers, do not undergo inactivation. The efficiency of transformation can be correlated with the sensitivity of a marker to inactivation after DNA uptake. A mutation which affects the efficiency of transformation is found to increase sensitivity to postuptake inactivation. The rate of inactivation is temperature-dependent. At temperatures of 20 and 45 C, marker inactivation can occur without concomitant recombination. During the uptake process, DNA is retained in an acid-insoluble form, indicating that the fate of Haemophilus influenzae DNA differs from the fate of transforming DNA in pneumococcus.

DNA, Bacterial↗