Structural characterisation of the complete cycle of sliding clamp loading in Escherichia coli

Xu ZQ, Jergic S, Lo ATY, Pradhan AC, Brown SHJ, Bouwer JC, Ghodke H, Lewis PJ, Tolun G, Oakley AJ, Dixon NE

Nature communications 15 (2024)

Movies in this entry were compressed to TIFF by EMPIAR Japan to save space and bandwidth.
The compression is lossless in that all pixel intensities remain exactly the same after decompression.
However, some metadata in the MRC header were lost.
The original files before compression are available from EMPIAR EBI.

The original deposition contained one gain reference file (*-gain-ref.MRC) for one movie.
Old versions of EPU had this wasteful behaviour, duplicating the same gain file many many times.
However, something is very weird about this deposition.
Analysis at PDBj (gain-references/GAIN-counts) indicated that this deposition contains
many different gain references. Because a single gain reference does not form a continuous
block when sorted by acquisition dates (GAIN-sorted-by-date), it is highly improbable that
different gain references represent genuine gain re-measurements. Moreover, the first few pixels of
all gain references are the same. If multiple gain references had really been collected during
the data collection session, all pixels would have had different values.
Thus, we (PDBj) presume that some gain reference files were corrupted during storage
or upload. To save storage space, we kept only a unique set of gain reference
files and deleted all redundant copies.

Original size:   6,408,451,055 kilobytes
Compressed size: 1,123,872,813 kilobytes