The "Danger Zone" (Max Path 7+) Finally, some ribosome brackets contain unprecedented obstacles, extending into the "Danger Zone" (8 in this set). Four of these proteins contain more segments than any published bracket on record (RF3 = 11 segments, S1 = 13 segments, EF-G = 17 segments, and IF2 = 22 segments), and these present the same common challenges as described for Hard and Medium brackets but in higher frequency. Two proteins (EF-Tu 1 and EF-Tu 2, of nearly identical sequence) use three separate V ligations in their top brackets (all performed at top-level between starting segments), and one (RF2) contains a V ligation followed by a poor thioester in its limiting path; these V ligations are likely to be significant yield bottlenecks. The most surprising member of this category is an 8-segment protein of modest length (S2, 241 aa) with one large segment bordered by two V ligations in every possible Aligator strategy, requiring these ligations to be performed consecutively and leading to the largest Max Path (11) in the ribosomal set.