Open AccessPurification and Properties of an Elongation Factor Functionally Analogous to Bacterial Elongation Factor Ts from Embryos of Artemia salina
Author(s) -
SLOBIN Lawrence I.,
MÖLLER Wim
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12142.x
Subject(s) - artemia salina , gtp' , elongation factor , brine shrimp , eukaryotic translation elongation factor 1 alpha 1 , ef tu , elongation , biology , biochemistry , ribosome , chemistry , enzyme , rna , ecology , materials science , organic chemistry , toxicity , ultimate tensile strength , gene , metallurgy
A protein factor which is functionally analogous to bacterial EF‐Ts was purified from developing embryos of the brine shrimp Artemia salina . The factor, designated as eEF‐Ts, has properties which are similar to EF‐1 β from pig liver. Specifically eEF‐Ts in our assay conditions stimulates EF‐1 L (eEF‐Tu)‐dependent binding of aminoacyl‐tRNA to ribosomes and eEF‐Tu and EF‐2 dependent poly‐phenylalanine synthesis 2.5–3‐fold. In addition eEF‐Ts is an efficient catalyst of a guanine nucleotide exchange reaction involving eEF‐Tu · GDP complexes and free GTP. We suggest that the latter activity explains the stimulation by eEF‐Ts of eEF‐Tu‐dependent functions. eEF‐Ts consists of a single polypeptide chain of M r 26 000, as judged by electrophoresis on acrylamide gels containing dodecylsulfate. However, the native enzyme consists largely of high‐molecular‐weight aggregates with sizes ranging from about 100 000 to greater than 200 000. Stable complexes of EF‐Tu and eEF‐Ts were formed by combining the two factors and these complexes were capable of binding GTP at low temperature (0–2 °C). Antibodies against the heavy form of elongation factor 1 cross‐reacted strongly with purified eEF‐Ts confirming our previous observation that EF‐1 in Artemia consists of eEF‐Tu · eEF‐Ts complexes. The relationship between EF‐1 and eEF‐Tu and eEF‐Ts is discussed.