Rationale:

The purpose of today’s lab was to create a project outline for our presentation as well as compare phage endolysin proteins to determine whether the M23 peptidase domain is highly conserved.

Tools:

• Word
• PhagesDB
• BLASTp
• RaptorX

Procedure

• An outline that highlighted the rest of the independent project was created.
• After that, multiple Arthrobacter phage lysin proteins were compared using PhagesDB, BLASTp, and RaptorX to compare their sequences.

Results

The following outline was created:

In addition to this, the following comparisons were drawn between different phage holin and endolysin proteins

Conclusions:

After viewing a wide array of different clusters of Arthrobacter phages it was discovered that only AM phages have the annotated endolysin protein containing the specific “HLH” sequence we have been looking for. The M23 Peptidase domain is not as highly conserved as expected, with the majority of phages, such as cluster AN, having a PGRP domain within their lysin proteins. It was also noted that there is variation of annotation comments regarding these supposedly similar proteins ranging from “Lysin A” to “endolysin”. It is unclear what decides these variations.

Next Steps:

Continue looking for the “HLH” sequence in M23 Peptidase domains in the rest of the listed phages. Also determine the defining characteristics of the PGRP domain.