Unidirectional growth of Salmonella flagella in vitro
In previous papers (Asakura, Eguchi & Iino, 1964, 1966), in vitro reconstitution of flagellar filaments from monomeric flagellins, using strains of Salmonella, was shown to be similar to crystallization. At physiological ionic strength and pH, reconstitution consists only of growth, that is, the...
Gespeichert in:
Veröffentlicht in: | Journal of molecular biology 1968-07, Vol.35 (1), p.227,IN7,231-230,IN14,236 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | In previous papers (Asakura, Eguchi & Iino, 1964, 1966),
in vitro reconstitution of flagellar filaments from monomeric flagellins, using strains of
Salmonella, was shown to be similar to crystallization. At physiological ionic strength and pH, reconstitution consists only of growth, that is, the polymerization of a monomer on to the ends of added fragments of flagella or “seeds”. The present study was undertaken to investigate whether growth takes place at two ends of each fragment or only at one of the two ends. For this purpose, we used two kinds of flagella, having
i- and
1,2-antigens, respectively, together with anti-flagella sera, anti-
i and anti-
1,2. Monomers and seeds derived from
i- and
1,2-flagella were cross mixed to produce heterogeneous filaments or “block copolymers”, which, after treatment with either one of the two antisera, were observed in an electron microscope with negative staining. When a product of copolymerization was treated with anti-
i, for example, a part of each filment containing
i-flagellin was uniformly labelled with the antibody and could be distinguished from another unlabelled part composed only of
1,2-flagellin. In a large number of the filaments observed, the great majority were of the form of
i-1,2; filaments of the form of
i-1,2-i or
1,2-i-1,2, were never found. On the other hand, it was shown that the addition of a small amount of seed to a mixture of
i- and
1,2-monomers results in the formation of long flagellar filments, each of which is uniformly labelled with anti-
i and anti-
1,2, respectively. In view of thes observations, it was concluded that during reconstitution flagellar filaments grow in a unidirectional manner.
Abram, Koffler & Vatter (Abst. 45,
2nd Int. Cong. Biophys., Vienna, 1966) have reported that when negatively stained fragments of flagella (
Bacillus) were observed in an electron microscope, only their distal ends appeared to be frayed. It will be shown in this paper that this end corresponds to the end where
in vitro growth takes place. |
---|---|
ISSN: | 0022-2836 1089-8638 |
DOI: | 10.1016/S0022-2836(68)80050-6 |