Data Item _pdbx_refine_component.connect

General

Item name
_pdbx_refine_component.connect
Category name
pdbx_refine_component
Attribute name
connect
Required in PDB entries
no
Used in currrent PDB entries
No

Item Description

The index of connectivity is the product of the (2Fobs-Fcal) electron density values for the backbone atoms (N, CA and C) divided by the average value for the structure. Low values (less than 1.0) of this index indicate breaks in the backbone electron density which may be due to flexibility of the chain or incorrect tracing. connect = [(D(xi)...D(xi))(1/N)] /<D>_all Where: D(xi) = (2*Fobs - Fcal) <D>_all is the averaged value of density for the structure. The product is for N atoms of group. Ref: Vaguine, A.A., Richelle, J. & Wodak, S.J. (1999). Acta Cryst. D55,199-205

Data Type

Data type code
float
Data type detail
float item types are the subset of numbers that are the floating numbers.
Primitive data type code
numb
Regular expression
-?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?