FEBRUARY 15-16 - MINUTES OF MEETING 
18 
X. PROPOSAL FOR CERTIFICATION OF A gt Aamal Lam439 Oam29.A B(A ALO-B) - 
DP50 supF AS AN EK2 SYSTEM . 
Drs. Tabor & Bode have asked for approval of Agt Aamal Lam 439 Oam.29AB in 
DP50 SupF as an EK2 host-vector system. The phage-host system depends for 
its containment on properties identical to that of XWES.aB: 1) the host- 
range and sensitivity to inactivation of lambda should limit its growth 
outside the laboratory; 2) temperature-denaturable (AcI857) repressor, 
inactive at body temperature, prevents stable association with the host; 
3) deletion of phage att region also prevents stable association with 
the host; 4) amber mutations in essential genes prevent lytic phage growth 
in all but specially designed hosts. 
The major change in this proposed vector is the substitution of the A~L~ 
and 0~ amber mutations for the W,E, and S mutations found in the AWES.AB 
phage. This change should improve the containment properties of the vector, 
since 1) only a host carrying both the sull and suIII suppressors will 
produce active phage; and 2) one can produce non-infectious phage particles 
under particular suppressing conditions. Tabor and Bode have tested their 
phage, using the tests specified by the Phage Working Group. 
Given the similarity of this phage-host system to those already approved, 
and the testing of the system done by Tabor and Bode, the RAC unanimously 
recommended approval of this host-vector system as an EK2 system. It can 
be considered a minor modification of the existing AWES.AB system. 
Dr. Campbell recommended that the vector should be named "AALO-B." 
XI. PROPOSAL FOR CERTIFICATION OF y!776 (pGLIOl) AS AN EK2 SYSTEM . 
Dr. Mark Ptashne requested on November 18, 1978 (608) that the plasmid 
pGLIOl be certified as an EK2 plasmid when propagated in x 1776. Approxi- 
mately half cf the original pBR322 plasmid has been replaced with a small 
95 base-pair piece of DNA from the lac operon of E. coli. 
The Host Plasmid Subcommittee of the RAC was polled by letter and recom- 
mended approval of the application. The application was briefly considered 
by the RAC. The RAC agreed that pGLIOl is a minor modification of pBR322 
and recommended by a vote of 14 to 0 with 2 abstentions that the proposal 
should be referred back to the Subcommittee to be acted upon under Section 
IV-E-l-b-(3)-(h) of the Guidelines. 
Executive Secretary's Note ; The Chairman of the Subcommittee reaffirmed 
on February 23, 1979 the recommendation that x J- 77 6 (pGLIOl) be approved 
as an EK2 system. 
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