Properties of native and nicked XXXX from Thermus thermophilus HB 8.

@entity3007 @entity71929 @entity4691 @entity526 @entity3006 @entity815 @entity37251
Two alternative procedures for the isolation of the @entity71929 from @entity4691 were compared and the properties of a specifically nicked EF-Tu . @entity3006 were examined in detail. Although the native elongation factor possessed similar catalytic activities in all reactions investigated as the protein isolated by Arai et al. [Eur. J. Biochem. 92, 509-519 and 521-531 (1978)] it could not be crystallized. The nicked EF-Tu, consisting of two associated fragments with molecular weights of 41000 and 8000 respectively, was active in binding @entity3006 , @entity3007 and in the formation of @entity815 -tRNAPhe . EF-Tu . @entity3007 ternary complex. However, it did not promote poly(U)-dependent synthesis of @entity37251 on @entity526 ribosomes. The isolated fragment of a molecular weight of about 41000 did not bind @entity3006 . This activity could be reconstituted with the supplement of the small 8000-Mr fragment. It is demonstrated that, in contrast to the native EF-Tu, the nicked EF-Tu forms high-molecular-weight aggregates. Cleavage of the polypeptide chain of EF-Tu from @entity4691 stimulates the crystallization of this protein.
