contact residues in barrel

1bia A
init 278 285 289 300 302 309

307/  309= 311$
+-= x*%+- %=


298-  300+
%=\^ *%=/\^?,&

280# 283x  285* 286, 287? 289%=$ %= %+=& +& +& +-^& 


276&  278%
*+\^?, x*+-=^$
 
314^
&%-\+&

ans: 276 278 280 285 289 298 300 302 309 311 314

seems like the bended strand is caused by a missed residue side chain (ex:Glu)
all 2x2 matrix are hydrophobic / side chains are inside.