ABSTRACT
Hypusination is an essential posttranslational modification unique to archaeal and eukaryotic protein synthesis initiation factor 5A (aIF5A and eIF5A, respectively). We have investigated the effect of the efficient hypusination inhibitor N(1)-guanyl-1,7-diaminoheptane (GC(7)) on four archaeal and one bacterial species. We found that (i) archaea are sensitive to GC(7), whereas the bacterium Escherichia coli is not, (ii) GC(7) causes rapid and reversible arrest of growth of the archaeon Sulfolobus acidocaldarius, and (iii) the growth arrest is accompanied by a specific reversible arrest of the cell cycle prior to cell division. Our findings establish a link between hypusination and sustained growth of archaea and thereby provide the framework to study molecular details of archaeal cell cycle in connection with in vivo functions of hypusine and of aIF5A and eIF5A.
