On the effects of structure and function on protein evolution
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Many proteins can be described as working machines that make sure that everything functions in the cell. Their specific molecular functions are largely dependent on their three-dimensional structures, which in turn are mainly predetermined by their linear sequences of amino acid residues. Therefore, there is a relation between the sequence, structure and function of a protein, in which knowledge about the structure is crucial for understanding the functions. The structure is generally difficult to determine experimentally, but should in principle be possible to predict from the sequence by computational methods. The instructions of how to build the linear proteins sequences are copied during cell division and are passed on to successive generations. Although the copying process is a very efficient and accurate system, it does not function correctly on every occasion. Sometimes errors, or mutations can result from the process. These mutations gradually accumulate over time, so that the sequences and thereby also the structures and functions of proteins evolve overtime. This thesis is based on four papers concerning the relationship between function, structure and sequence and how it changes during the evolution of proteins. Paper I shows that the structural change is linearly related to sequence change and that structures are 3 to 10 times more conserved than sequences. In Paper II and Paper III we investigated non-helical structures and polar residues, respectively, positioned in the nonpolar membrane core environment of α-helical membrane proteins. Both types were found to be evolutionary conserved and functionally important. Paper IV includes the development of a method to predict the residues in α-helical membrane proteins that after folding become exposed to the solvent environment.
Place, publisher, year, edition, pages
Stockholm: Department of Biochemistry and Biophysics, Stockholm University , 2010. , 48 p.
protein, structure, function, evolution, membrane
Biochemistry and Molecular Biology
Research subject Biochemistry
IdentifiersURN: urn:nbn:se:su:diva-35872ISBN: 978-91-7155-980-7OAI: oai:DiVA.org:su-35872DiVA: diva2:288611
2010-02-19, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Ben-Tal, Nir, Professor
Elofsson, Arne, Professor
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.2010-01-282010-01-202014-11-10Bibliographically approved
List of papers