Abstract
CRM+ nonsense mutations, as described for E. coli K12 lacZ, in theory permit determination of the direction of transcription of an isolated gene. In the hope of utilising this approach to confirm that the E gene of the E. coli K12 argECBH cluster is transcribed in the opposite direction from the CBH unit, 30 argE mutations were investigated immunologically and genetically. Only three, E1, E25 and E26 (which map close together towards the left-hand end of the gene), were found to be CRM+. Co-suppression of each argE mutation with known strongly polar lacZ amber, ochre and UGA mutations was looked for to distinguish missfense from nonsense argE's, Arg+ revertants being screened for Lac+ and Mel+ phenotypes. Of 16 mutations not hitherto characterised as nonsense, frameshift or large deletions, only three, E1, E25 and E26, appeared to be missense. Three of the nonsense mutations were also streptomycin suppressible. It appears, therefore, that among argE mutants so far studied the correlation between CRM+ and missense is complete, so that the projected method for determining the direction of transcription of argE could not be applied.
References
Aug 4, 1978·Molecular & General Genetics : MGG·P L Bergquist, P Truman
Apr 1, 1977·Journal of Bacteriology·C G Miller, D Zipser
May 3, 1978·Molecular & General Genetics : MGG·A BoyenN Glansdorff
Apr 5, 1976·Journal of Molecular Biology·A P Bretscher, S Baumberg
Sep 1, 1976·Journal of Bacteriology·D Zipser, P Bhavsar
Sep 15, 1975·Molecular & General Genetics : MGG·R CuninM Crabeel
Jan 1, 1972·Molecular & General Genetics : MGG·G A Jacoby
Jan 1, 1972·Molecular & General Genetics : MGG·D ElseviersN Glansdorff
Dec 1, 1972·Bacteriological Reviews·B J Bachmann
Jun 20, 1973·Nature: New Biology·A I Bukhari, D Zipser
Feb 1, 1974·Journal of Bacteriology·C J PanchalA Guha
Mar 1, 1974·Journal of Molecular Biology·P H PouwelsN Glansdorff
Jun 7, 1974·Nature·J F Atkins, S Ryce
Sep 25, 1974·Journal of Molecular Biology·P JargielloP Hoffee
Jan 1, 1969·Molecular & General Genetics : MGG·J Langridge, J H Campbell
Jan 1, 1969·Molecular & General Genetics : MGG·R CuninN Glandsdorff
Jan 1, 1970·Molecular & General Genetics : MGG·S Baumberg
Dec 19, 1970·Nature·R Goldschmidt
Dec 19, 1970·Nature·T PlattK Weber
Dec 1, 1971·Journal of General Microbiology·S Baumberg, E Ashcroft
Jan 1, 1970·Annual Review of Genetics·L Gorini
Apr 14, 1968·Journal of Molecular Biology·A V Fowler, I Zabin
Feb 1, 1970·Journal of Bacteriology·A P BergI Zabin
Jan 1, 1966·Annual Review of Microbiology·L Gorini, J R Beckwith
May 1, 1965·Proceedings of the National Academy of Sciences of the United States of America·S BaumbergH J Vogel
Nov 14, 1966·Journal of Molecular Biology·H J WhitfieldB N Ames