Thanks I appreciate your answer . I understand it can be the chain of the protein, but I was confused because some the secondary structure in the file has different chain of protein with the same PDB id.
Meaning of the header in secondary structure of protein?
I download Secondary Structure Files from https://www.rcsb.org/pdb/static.do?p=download/http/index.html#ss. I want to know what does it mean the letter after PDB code in the secondary structure(header)?
>102L:A:secstr
HHHHHHHHH EEEEEE TTS EEEETTEEEESSS TTTHHHHHHHHHHTS TTB HHHHHHHHHHHHHHH
HHHHHH TTHHHHHHHS HHHHHHHHHHHHHHHHHHHHT HHHHHHHHTT HHHHHHHHHSSHHHHHSHHHHHHH
HHHHHHSSSGGG
I mean the letter 'A' in this case. Thanks.
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PDB identifiers usually consist of the 4-length alphanumeric identifier and the protein chain. I'm guessing 102L is the PDB identifier and A is the protein chain.
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Help for secondary structure files is on this page.
Thanks for your reply. I read this link and many others, but I did not get the answer.