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Figure 2.
A fragment of multiple alignment of E-spectrin sequences with the
consensus sequence.
2.2 The global multiple alignment
The aim of the multiple alignment construction is to create a picture of identities,
similarities and differences of primary structures being compared. It is made by aligning
sequences in the way that several amino acids in the same positions are relate with each
other as close as possible. It is a three-colour combination; conservatives positions are
negatives, residues semihomologous to them are light grey and residues semihomologous to
each other - dark grey (Fig. 2.).
The global multiple alignment of E-spectrin protein family and the consensus
sequence concern 2668 positions (34 pages A4), that is why showing the whole alignment
in this paper is impossible
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.
The rate of homology within the E-spectrin family is estimated as moderated, c.a.
50% (according to the consensus sequence). There are different parts of the alignment to be
noticed: parts with a very high level of identity - these are whole fragments of conservative
positions and parts with a low rate of homology. The N-terminal fragment (positions 45-
695) has a high level of identity - there are continuous fragments of conservative residues,
locally interrupted by single semihomologous positions. This conservative nature of this
fragment is probably determined by the protein's functions. A domain homologous to
calponine (CH domain) is located in this area - responsible for binding action. The CH
domain plays the main role of this protein, crucial for the existence of the cell.
There is a gap in positions: 697-706 (9 positions) - only 12 sequences has amino
acid residues in those positions. These are very characteristic sequences - rich in glycine
and alanine residues. The middle area of the global multiple alignment is rich in
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The whole multiple alignment is accessible in B.S. Thesis: “£-Spectrins and their homologues -
comparative studies and consensus sequence construction” - A. Fogtman, Institute of Biochemistry and
Molecular Biology, University of Wroclaw, Poland, 2003.
