Protein Structure, Secondary

Secondary Protein Structure; Conformation, Protein alpha-Helical; Conformation, Protein beta-Sheet; Conformation, Protein beta-Strand; Conformation, alpha-Helical Protein; Conformation, beta-Sheet Protein; Conformation, beta-Strand Protein
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.