Study of the functionality of the Helicobacter pylori trans-translation components SmpB and SsrA in an heterologous system

Table 4 Phenotypes of the different mutants of E. coli ssrA

E. coli SsrA version	Effects on SsrA	SsrA tag appended to truncated proteins	EOP^§	Reference
SsrA^WT	Wild type	ANDENYALAA	1	[14, 15]
SsrA^resume	Substitution of the resume codon by a stop codon	None	1.3 × 10^-5	[14]
SsrA^wobble	Absence of alanylation of the tRNA-like domain of SsrA	None	5 × 10^-5	[28]
SsrA^SmpB	Absence of interaction between SsrA and SmpB	None	N.D.
SsrA^DD	Substitution of the last two alanine residues of the tag by two aspartate residues	ANDENYALDD	0.5 -- 0.1	[28]
SsrA^STOP	Two stop codons added after the resume codon	Minimal tag added	0.9	[14]

^§ EOP is the ratio between the titer of phage on a lawn of bacteria expressing one of the indicated SsrA versions and the titer of phage on a wild type bacterial lawn; N.D.: Not determined.

ISSN: 1471-2180