The aflatoxin in this round is a little different. The new version doesn't have a calcium, so it's one atom smaller. Also, the atom numbers have changed.
Previously, the oxygen at what is now atom 6 (formerly atom 23) was bonded to calcium. The calcium is no longer present. The heavy atoms are 1 to 24, and 25 to 37 are hydrogen.
Puzzle 1538 aflatoxin: The calcium atom seen in previous rounds is gone.
See the puzzle 1440 comments for the old structure.
Thanks to SuperNova185 for spotting the change.
The view seen here is Stick + H with EnzDes coloring. Atom Explorer v1.0 was used to enumerate the atoms. The configuration file 0002005425.ir_puzzle.params is in plaintext, and has ATOM records that identify the atoms in order.
As the comments mention, the protein has been trimmed way down. There are now several long straight "struts" that connect the different parts. The struts are just a few segments long, and have huge negative scores, mostly based on ideality. For example, segments 13 and 14 each are scoring around -750,000. Scoring has been adjusted to compensate.
Puzzle 1538 protein with "struts"