Institute of Enzymology, BRC, Hungarian Academy of Sciences, PO Box 7, H-1518 Budapest, Hungary. zsuzsa@enzim.hu|Institute of Enzymology, BRC, Hungarian Academy of Sciences, PO Box 7, H-1518 Budapest, Hungary. zsuzsa@enzim.hu|Institute of Enzymology, BRC, Hungarian Academy of Sciences, PO Box 7, H-1518 Budapest, Hungary. zsuzsa@enzim.hu|Institute of Enzymology, BRC, Hungarian Academy of Sciences, PO Box 7, H-1518 Budapest, Hungary. zsuzsa@enzim.hu