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new antirestriction protein type

| posted 15 Jul, 2019 20:07
for phage Saftant gene 68 (45610-45200) we have found good evidence for an anti-restriction protein but the matches are not to ArdA-like like proteins but rather a second type of antirestriction proteins called OCR. The OCR-type anti-restiction protein is found in phage T7 and is one of the first protein products expressed following infection (see this NAR paper). OCR type are typically shorter (~120 AA) than ArdA (170-180) and have sufficiently different crystal structures that I think we should avoid using the ArdA-like approved term for this protein. Here is the image of the two structures side by side.

For details, see phage saftant in PECAAN but briefly saftant 68 hits by hhpred with 94.4% probability to the crystal of gene 0.3 protein from phage T7 (D chain of this crystal) with ~90% coverage of both subject and query. I would propose either adding this second type as an approved function "antirestriction protein, OCR-like" or simply adding another term without the ArdA-like (i.e. "antirestriction protein" ) to avoid over annotation.
Edited 15 Jul, 2019 20:10
| posted 16 Jul, 2019 12:51
We found a homolog in a Bacillus phage we just annotated, I believe, and called it: DNA mimic domain containing protein, since the coding sequence was larger than the domain you describe above, but contained it. But if it is the right size, perhaps DNA mimic protein might be a good choice?

Edited 16 Jul, 2019 13:49
| posted 16 Jul, 2019 13:56
Hi All,
Debbie and I spoke about this one, and decided to go with "antirestriction protein, OCR-like" for consistency.
I do like the "DNA mimic" label– it is far more descriptive of what the protein actually does. Maybe we need to start writing some of function glossary to capture what these do.

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