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
SsrAWT	Wild type	ANDENYALAA		1	[14,15]
SsrAresume	Substitution of the resume codon by a stop codon	None		1.3 × 10-5	[14]
SsrAwobble	Absence of alanylation of the tRNA-like domain of SsrA	None		5 × 10-5	[28]
SsrASmpB	Absence of interaction between SsrA and SmpB	None		N.D.
SsrADD	Substitution of the last two alanine residues of the tag by two aspartate residues	ANDENYALDD		0.5 -- 0.1	[28]
SsrASTOP	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.