The occurrence of progesterone 5β-reductase is not limited to the angiosperms: a functional gene was identified in Picea sitchensis and expressed in Escherichia coli

New Zealand Journal of Forestry Science

Table 2 A compilation of individual parameters of recombinant P5ßR enzymes from Picea sitchensis (rPsP5ßR), Arabidopsis thaliana (rAtP5ßR), Erysimum crepidifolium (rEcP5ßR), and Medicago truncatula (rMtP5ßR) with progesterone, 2-cyclohexen-1-one, and methyl vinyl ketone, respectively

Enzyme	Substrate	K _M (μM)	k _cat (min⁻¹)	k _cat/K _M (min⁻¹ M⁻¹)	Preference
rPsP5βR	Progesterone	111	0.59 ± 0.02	0.0053	88.9
	2-Cyclohexen-1-one	88	41.6 ± 3.05	0.4727
	Methyl vinyl ketone	75	6.0 ± 0.25	0.0800
rAtP5βR^a	Progesterone	268	10.11 ± 2.99	0.0373	15.5
	2-Cyclohexen-1-one	116	66.85 ± 3.78	0.5775
	Methyl vinyl ketone	n.d.	n.d.	n.d.
rEcP5βR^b	Progesterone	77	0.60	0.0077	36.4
	2-Cyclohexen-1-one	518	147	0.2837
	Methyl vinyl ketone	344	43.8	0.1273
rMtP5βR^c	Progesterone	144	30.0	0.2083	1.1
	2-Cyclohexen-1-one	82	19.2	0.2317
	Methyl vinyl ketone	136	32.4	0.2382

Substrate preference was calculated dividing k _cat/K _M 2-cyclohexen-1-one by k _cat/K _M progesterone. The labelled values were taken from the indicated references. The results represent mean values based on three replications done
n.d. not determined
^aBauer et al. 2012
^bMunkert et al. 2011
^cMunkert et al. 2015