Table 1.

Brief description of various PDB chains databases and number of protein chains present in respective database

Sub-Database	Software used for assignment	Types of information in database	Number of protein chains
			Unique	70 %	40 %
SecStructure	DSSP	Regular secondary structure	97216	30642	24211
		Accessible surface area
BetaTurn	Promotif	Beta Turns and types	90331	27763	21075
GammaTurn		Gamma turns	72124	22971	16584
BetaBulge		Beta bulges in proteins	56186	17753	12944
BetaHairpin		Beta hairpins	72420	21623	15477
PsiLoop		Psi loops	13351	4382	3151
DNAinteract		DNA binding sites	2123	849	757
RNAinteract		RNA binding sites	1437	885	650
LigandInt	LPC	Ligand interacting residues	51615	17952	13525
MetalInt		Metal binding residues	22629	9160	7286