Although the active site of ASV integrase does not undergo significant conformational changes on binding the required metal cofactor, that of HIV-1 does.
Human membrane cofactor protein (CD46) acts as a cellular receptor for measles virus.
It tells you a bit about the catalytic activity of the enzyme and its cofactor Pyridoxal Phosphate.
From the value of A we may separate those members which contain a particular element a ik as a factor, and write the portion aik A ik; A k, the cofactor of ar k, is called a minor of order n - i of the determinant.
Hence anAu = auk t a22a33...ann, where the cofactor of an is clearly the determinant obtained by erasing the first row and the first column.