A cell-free amino acid incorporating system from an extremely halophilic bacterium

Behaviour of phenylalanyl‐tRMA from Halobacterium cutirubrum on BD‐cellulose

“…To measure the radioactivity in fractions from the column, 1 ml samples of the fractions were each mixed with 1 ml of cold water, 0.1 ml of a solution of serum albumin (5 mg/ ml), to act as carrier, and 2 ml cold aqueous 10% trichloroacetic acid (w/v). After standing in ice for 10-15 min, the precipitated material was washed once with 4 ml of cold 5% trichloroacetic acid by centrifugation, collected on a Millipore filter (0.45/zrn), washed again with 3 ml of 5% trichloroacetic acid, dried in an oven for 20 min at 65 ° and assayed for radioactivity in a liquid scintillation counter as described previously [3]. Estimation of the phenylalanine acceptor activity of the tRNA was performed in concentrated salt solution by the method of Griffiths and Bayley [5].…”

“…In order to extend our studies on the mechanism of protein synthesis in the extremely halophilic bacterium Halobacterium cutirubrum, [3][4][5] the purification of phenylalanine specific tRNA was undertaken. This report describes the behaviour of charged isoaccepting species of tRNA Phe on BD-cellulose.…”

A highly efficient poly(U)‐dependent poly(Phe) synthesis system for the extreme halophile archaebacterium Halobacterium halobium

“…To test whether this 3-site model (valid for E. coli ribosomes) is a general description of the ribosomal elongation cycle, we decided to analyse tRNA binding and translocation in ribosomes of a different kingdom, the archaebacteria. [3,4], and 2-6 Phe/ribosome per h in systems with other archaebacterial species [5-71. Here, we describe an in vitro system for Halobacterium halobium with a synthesis rate of 20-35 Phe/ribosome per h and an error frequency of only 0.5%.…”

Acidic ribosomal proteins from the extreme halophile,Halobacterium cutirubrum

“…Notable exceptions are the acidic ribosomal proteins from the extreme halophilic bacterium, Halobacterium cutirubrum [7,8]. While it appears that the transition to halophilism has been accompanied by a drastic shift in the charge of these ribosomal polypeptides, there has been considerable conservation in those structural features which allow for the usual protein-protein and protein-nucleic acid interactions required in the assembly and translation properties of the ribosomal unit [9][10][11]. The identification of the protein moieties involved in these and other interactions in the halophile ribosome requires a rapid and reproducible screening method for the separation, enumeration and identification of these acidic polypeptides in the complex ribosomal protein mixtures.…”