In a parallel arrangement, all of the N-termini of successive strands are oriented in the same direction; this orientation is slightly less stable because it introduces nonplanarity in the inter-strand hydrogen bonding pattern. It is rare to find less than five interacting parallel strands in a motif, suggesting that a smaller number of strands may be unstable.
1N55: Is involved in the catalysis of the Reaction: D Glyceraldehyde 3 Phosphate = Glycerone Phosphate.
1TWD: Is a TIM-like protein that has metal binding capabilities. The metal that is bound by 1TWD is always copper.