Structural proteins of Enterococcus faecalis bacteriophage φEf11

Figures & data

Figure 1. SDS-PAGE analysis of proteins from purified bacteriophage φEf11(Δ61-65, FL1C39-44). Lane 1, molecular weight markers (Fermentas Broad Range Protein Ladder; Lanes 2 and 3, dissociated, purified bacteriophage φEf11(Δ61-65, FL1C39-44).

Figure 2. Comparison of deduced amino acid sequences of bacteriophage φEf11 gene products with amino acid sequences of peptides detected in MS analysis of SDS-PAGE-separated bacteriophage φEf11(Δ61-65, FL1C39-44) virion proteins. Black lettering is the ORF DNA base sequence, Blue lettering is the deduced gene product amino acid sequence, Red or Green lettering is the amino acid sequence of the peptides detected by MS analysis of the material in the bands seen in the SDS-PAGE-separated φEf11(Δ61-65, FL1C39-44) virion proteins. (A) ORF23/SDS-PAGE Band 2 protein. (B) ORF10/Bands 6 and 8 proteins (Green is SDS-PAGE band 6 material, Red is SDS-PAGE band 8 material). (C) ORF15/Band 10 protein. (D) ORF8/Band 11 protein.

Table 1. Summary of phage φEf11(Δ61-65, φFL1C 39-44) virion proteins predicted from DNA sequence and detected by SDS-PAGE.

Band No./ORFNo.^*	Predicted function of ORF product	MW predicted from DNA sequence	MW determined by SDS-PAGE analysis
2 / 23	Anti-receptor	63,273	73,000 – 74,000
6 / 10	Major head protein	37,324	41,000 – 43,000
8 / 10	Major head protein	37,324	38,000 – 39,000
9 / —
10 / 15	Major Tail protein	21,542	30,000 – 28,000
11 / 8	Scaffold protein	23,446	27,000 – 27,000

* ORF assignment of the protein in each band made by comparing the deduced gene product amino acid sequence with the amino acid sequences of the peptides detected in each band by MS.

Figure 3. Map of head and tail morphogenesis region of bacteriophage φEf11 genome.

Figure 4. Region of 3’ end of ORF 10. The 0 reading frame is shown in the upper nucleotide sequence. Proposed slippery sequence (AAAAAAA) is indicated by a solid line box. The ORF stop codon is indicated by *. A potential −1 frameshift would result in the nucleotide sequence shown below. In the shifted reading frame, the original stop codon would be converted into 2 amino acid-specifying codons (ATA and GAA), and the protein translation product would be extended by 21 amino acids.

Figure 5. Potential secondary structure of mRNA in region immediately downstream of the proposed slippery sequence and terminal codon of ORF 10, as determined by MFOLD analysis. Initial ΔG = −20.10 kcal/mol. Proposed slippery sequence is indicated by solid line box and 0 frame stop codon is indicated by dotted line box.