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Southern Illinois University at Carbondale
Carbondale, Illinois 62901-6508

Department of Microbiology
618-536-2349

  
  

NOV 13 #387

i
Ree ogy IL ‘

November 11, 1987

Dear Dr. Lederberg:

Thank you for your letter: I am afraid that the answers to most of
your latest questions are still uncertain. I dont know anything
about chloroacetate. However, John Guest in Sheffield, England made
fluoroacetate resistant mutants. These are deficient in acetate
kinase and/or phosphot ransace#¥lase. They cannot grow on acetate or
ferment sugars anaerobically to produce acetic acid. They map at
pta/ack (50 min). These are quite different in their properties
from either the choloroacetaldehyde or bromo-propanol mutants.

The chloroacetaldehyde resistant mutants are specifically defective
in alcohol and acetaldehyde dehydrogenase (both activities are
probably due to the same protein). They map at adhE (27 min).

The bromopropanol mutants are not affected in alcohol/acetaldehyde
dehydrogenase, or in anthing else obvious. They are totally
dependent on BuOH or BrPrOH on succinate as carbon source whereas on
glucose they grow almost normally without any solvent added. I
haven“t done any incorporation studies ~ we stored the
BuOH-dependent strains away and worked mostly on the adh mutants.

We haven“t investigated formate hydrogenlyase in them either. I
suspect that some of the fluoractate mutants have multiple defects
in anaerobic growth but as far as I°m aware no one has assayed FHL
yet — thanks for the suggestion ~ I will try and check this sometime
not too far distant.

I was sorry to hear you were to busy to present a seminar here this

year. I am only in charge of seminars until May 1988, but if you ——
were willing to arrange a visit sometime next academic year

(1988-1989), we co}d fix up a date a long time ahead for the next

Ogur seminar.

Yours sincerely,

Dovel Chock.

David P. Clark