Computational validation of residue conservation
Details of the CENP-HK binding interface at the C-terminal was revealed
in the crystal structure of the fungal HIK complex (5Z08). The side
chain of ILE-205, ILE-211 and LEU-219 from th CENP-H were shown to
insert into the hydrophobic pocket of th CENP-K which is
surrounded by several residues including, LEU-177, TRP-179, PHE-180,
HIS-184, ILE-270 and PHE-300. On the CENP-HI interface, th CENP-H
uses its contacting helix (HH2) in interacting with thect CENP-INT HEAT repeat. A salt bridge was
reported to be formed between the ARG-220 of th CENP-H and the
GLU-86 of ct CENP-INT, while the LEU-224 of was
reported to insert into the ct CENP-INThydrophobic pocket (surrounded by LEU-89, VAL-126 and VAL-130) [14].
The alignment of amino acid sequences from different orthologs of CENP-H
(T. terrestris, G. gallus, O. aries, R. norvegicus, M. musculus
and H. sapiens ) revealed a high degree of conservation in favour of the
CENP-K and -I-binding residues of the protein, which in human correspond
to LEU-219, VAL-225, LEU-233, LYS-234 and LEU-238 [14]. Using
ConSurf, we validated the degree of conservation of the reported
residues in the hs CENP-H model. The output depicted that all the
five reported residues (LEU-219, VAL-225, LEU-233, LYS-234 and LEU-238)
are conserved with varying degrees of conservation (Figure 4).