A Life with Yeast Molecular Biology - Prof. Dr. Horst Feldmann

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H. FELDMANN
In fact, we had solved the primary structures of two very closely
related molecules not completely separated by counter-current
distribution, termed Ser I and Ser II. But when I analyzed each of
the side fractions, it became clear that Ser I and Ser II, both
present in about equal amounts in our preparations, differed in
only three nucleotides (one in the TCC loop and two in the extra
loop) [14]. Later, when the complete sequence of the genome had
been determined (see below), no gene for Ser I could be identified
in lab strain aS288C but 11 copies for Ser II. The ‘‘secret’’ of Ser I
has never been solved. Probably, commercial brewer’s yeast we
used (C836) consisted of two related species. Along with the
sequence determination, I became involved in characterizing the
structures of two ‘‘odd’’ nucleotides, N 6 -acetylcytidin and
isopentenyl-adenosin (iPA), the latter of which we had found in
serine tRNA at the 3u side of the anticodon [15].
A report on the serine tRNAs [16] was included in the Cold
Spring Harbor Symposium on Quantitative Biology devoted to the
‘‘Genetic Code,’’ 1966. This offered me the splendid opportunity
not only to follow the current achievements reported at this venue
but to visit a number of laboratories in the US, at the University
of Albany, at the Roswell Park Memorial Institute in Buffalo, at
the University of Illinois in Urbana, at Oak Ridge Natl. Lab. in
Tennessee, and at the University of Chicago. I also visited old
friends from Genetics, Fritz Melchers at the Salk Intitute in
La Jolla, San Diego, Max Delbrück with his wife Manny and
Charles David at CalTech in Pasadena, and Thomas Trautner at
the UCSF, Berkeley. In order to take the cheapest way of flying to
New York and back, I choose a prop-jet of Icelandic Airlines
starting from Luxembourg, which offered a 24 hour stop-over in
Reykjavik. There I met Johann Gudmundsson, who had obtained
his diploma in chemistry during my time in Cologne and had
taken a position in a fish cannery in Reykjavik. On the spot, he
managed a sight-seeing tour in his veteran Ford car and showed
me around a lot of the impressing country. This was ‘‘Iceland in
24 hours,’’ but the impressions from this intense trip should stay
for the rest of my life.
With so many contacts and after having done some work in my
‘‘new field,’’ it would have been easy for me to find a post-doctoral
position in the United States, but just during my time in Genetics
our two daughters had been born (Barbara in 1963 and Miriam in
1966), and so we preferred to stay in old Germany.