TABLE 3.
Deduced sequences and functions of mutated FasA proteins
| Sitea | Mutationb | Wild-type sequencec | Mutated sequenced | Fimbriatione |
|---|---|---|---|---|
| 29 | 2I, 1S | 224 AAC AAC ACC 232 | 224 AAC AGG GCC CAC 235 | ++ |
| 28 Asn Asn Thr 30 | 28 Asn Arg Ala His 31 | |||
| 97 | 2I | 428 ATT GCT GGT AAT AAT 442 | 428 ATT GGG CCC GCT 439 | ++ |
| 96 Ile Ala Gly Asn Asn 100 | 96 Ile Gly Pro Ala 99 | |||
| 2I, 2D | 428 ATT GGG CCC AAT 439 | ++ | ||
| 96 Ile Gly Pro Asn 99 | ||||
| 141 | 2I | 563 GTA CCT GTG 571 | 563 GTA GGG CCC CCT 574 | + |
| 140 Val Pro Val 142 | 140 Val Gly Pro Pro 143 | |||
| 192 | 2I, 3D, 14A | 713 GCA GGT ACA CCG TAA 727 | 713 GCA GGG CCC GTA …f | ++ |
| 191 Ala Gly Thr Pro - 194 | 191 Ala Gly Pro Val … | |||
| 1D | 713 GCA GGG CCC TAA 724g | ++ | ||
| 191 Ala Gly Pro - 193 | ||||
| 193 | 2I, 2D, 15A | 716 GGT ACA CCG TAA 727 | 716 GGT AGG GCC CCC …h | ++ |
| 192 Gly Thr Pro - 194 | 192 Gly Arg Ala Pro … | |||
| 2D, 4A | 716 GGT AGG GCC CTA AGC TAA 733g | − | ||
| 192 Gly Arg Ala Leu Ser - 96 |
Insertion site in the FasA protein sequence, corresponding to the first altered residue in the sequence.
Data are the numbers of amino acid residues which were inserted (I), deleted (D), or substituted (S) in FasA or which were added (A) at the carboxy terminus of FasA because of a frameshift just upstream of the stop codon as a result of fasA mutagenesis.
fasA and FasA sequences. Numbers refer to the indicated first and last nucleotides or amino acid residues of the original sequences.
Linker insertion sites with resulting mutations in fasA and deduced amino acid changes. Numbers refer to the indicated first and last nucleotides or amino acid residues of the mutated sequences. Linker DNA (ApaI restriction site) and new amino acids are in italics.
Exported and assembled fimbriae quantitated by seroagglutination with anti-987P antibodies. ++, strong reaction during the first 10 s, equivalent to the reaction with bacteria expressing the wild-type FasA protein; +, weak reaction after 10 s; −, no reaction for 1 min.
Frameshift resulting in the substitution of 16 residues (not all shown) for the 3 residues at the carboxy terminus of wild-type FasA.
Mutants obtained by site-directed mutagenesis to remove the long residue tail at the carboxy terminus of mutated FasA.
Frameshift resulting in the substitution of 17 residues (not all shown) for the 2 residues at the carboxy terminus of wild-type FasA.