caa a22 4500 605506027 CHVBK 20210128100624.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00253-014-6345-8 doi (NATIONALLICENCE)springer-10.1007/s00253-014-6345-8 The role of N1 domain on the activity, stability, substrate specificity and raw starch binding of amylopullulanase of the extreme thermophile Geobacillus thermoleovorans [Elektronische Daten] [M. Nisha, T. Satyanarayana] In order to understand the role of N1 domain (1-257 aa) in the amylopullulanase (gt-apu) of the extremely thermophilic bacterium Geobacillus thermoleovorans NP33, N1 deletion construct (gt-apuΔN) has been generated and expressed in Escherichia coli. The truncated amylopullulanase (gt-apuΔN) exhibits similar pH and temperature optima like gt-apu, but enhanced thermostability. The gt-apuΔN has greater hydrolytic action and specific activity on pullulan than gt-apu. The k cat (starch and pullulan) and K m (starch) values of gt-apuΔN increased, while K m (pullulan) decreased. The enzyme upon N1 deletion hydrolyzed maltotetraose as the smallest substrate in contrast to maltopentaose of gt-apu. The role of N1 domain of gt-apu in raw starch binding has been confirmed, for the first time, based on deletion and Langmuir-Hinshelwood kinetics. Furthermore, N1 domain appears to exert a negative influence on the thermostability of gt-apu because N1 truncation significantly improves thermostability. Springer-Verlag Berlin Heidelberg, 2015 Amylopullulanase nationallicence Truncation nationallicence Geobacillus thermoleovorans nationallicence X25 domain nationallicence Thermostable nationallicence Raw starch binding nationallicence Nisha M. Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, 110 021, New Delhi, India aut Satyanarayana T. Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, 110 021, New Delhi, India aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/13(2015-07-01), 5461-5474 0175-7598 99:13<5461 2015 99 253 https://doi.org/10.1007/s00253-014-6345-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6345-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nisha M. Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, 110 021, New Delhi, India aut NATIONALLICENCE 700 1- Satyanarayana T. Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, 110 021, New Delhi, India aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/13(2015-07-01), 5461-5474 0175-7598 99:13<5461 2015 99 253