Example sentences for: bchh
How can you use “bchh” in a sentence? Here are some example sentences to help you improve your vocabulary:
The initial step of the insertion can proceed in the presence of either Mg.ATP or a non-hydrolyzable ATP-analog and involves oligomerization of the BchD and BchI subunits to form an oligomeric ring of AAA protomers that resembles the ring structure of NSF and other AAA proteins [ 14 32 ] . The second step of the insertion involves an obligatory hydrolysis of ATP that is tightly coupled with the transfer of the chelated Mg 2+to the protoporphyrin ring by BchH [ 49 ] . Although the details differ from midasin, particularly with respect to the subunit composition of the AAA ring, this chelation reaction provides a structural model suggesting that the function of the midasin M-domain may be to regulate the ATPase activity of the AAA protomers in the pseudo-hexameric ring and thus couple ATP hydrolysis to the binding of a protein ligand at the MIDAS site.
The BchI subunit also possesses a single AAA protomer, but contains no MIDAS domain [ 32 ] . The third subunit BchH is able to bind the protoporphyrin ring in either the presence or absence of ATP.
This basic domain organization shows a striking parallel to that of magnesium chelatase, a heterotrimeric enzyme containing BchD, BchI and BchH subunits, that performs ATP-dependent insertion of Mg 2+into the protoporphyrin IX ring in the course of chlorophyll biosynthesis [ 49 ] . In particular, the BchD subunit resembles midasin in possessing a single AAA protomer close to its NH 2 -terminus, together with a short aspartate-glutamate-rich region and a MIDAS-containing domain at its carboxy-terminus.
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