Table 2.

Data collection and refinement statistics

Lactaldehyde dehydrogenase	Unliganded	NADH-lactate complex	NADPH complex
Resolution, Å	50 - 2.2	50 - 2.1	50 - 2.7
Total/unique reflections, > 0 σ(I)	63,439/32,461	67,837/34,320	30,815/15,617
Completeness, % (overall/outer shell)	99.0/99.1	93.7/92.8	89.6/100
Rmerge (overall/outer shell)a	0.117/0.529	0.122/0.542	0.139/0.416
I/σ(I) (overall/outer shell)	33.6/6.3	17.1/3.6	22.6/6.9
No. of reflections, work/test	30,866/1,595	31,908/2,412	14,526/1,091
R/Rfreeb	0.222/0.252	0.200/0.234	0.212/0.253
Protein atomsc	3,663	3,666	3,666
Water moleculesc	109	221	32
Ligand atomsc	0	92	47
Sulfate ionsc	2	2	2
R.m.s. deviations
Bond lengths, Å	0.006	0.006	0.007
Bond angles, °	1.2	1.4	1.3
Dihedral angles, °	22.7	22.6	22.0
Improper dihedral angles, °	0.81	0.94	0.97
Mean B values, Å2
Protein main chain atoms	31	25	30
Protein side chain atoms	34	28	32
Solvent	30	27	18
Sulfate ions	68	61	94
NAD(P)H	---	34	46
Lactated	---	43	---
Ramachandran plot:e number/percentage of residues with backbone conformations
Allowed	376/91.3	374/90.7	355/86.1
Additionally allowed	33/ 8.0	34/ 8.3	49/12.0
Generously allowed	1/ 0.2	1/ 0.2	5/ 1.2
Disallowed	2/ 0.5	3/ 0.7	3/ 0.7

^a${\mathrm{R}}_{\text{merge}}=\sum \mid \mathrm{I}-\langle \mathrm{I}\rangle \mid ∕\sum \mid \mathrm{I}\mid$, where I is the observed intensity and $\langle \mathrm{I}\rangle$ is the average intensity calculated for replicate data.

^bCrystallographic R factor, $\mathrm{R}=\sum (\mid {\mathrm{F}}_{\mathrm{o}}\mid -\mid {\mathrm{F}}_{\mathrm{c}}\mid )∕\sum \mid {\mathrm{F}}_{\mathrm{o}}\mid$, for reflections contained in the working set. Free R factor, ${\mathrm{R}}_{\text{free}}=\sum (\mid {\mathrm{F}}_{\mathrm{o}}\mid -\mid {\mathrm{F}}_{\mathrm{c}}\mid )∕\sum \mid {\mathrm{F}}_{\mathrm{o}}\mid$, for reflections contained in the test set excluded from refinement (8% of total). $\mid {\mathrm{F}}_{\mathrm{o}}\mid$ and $\mid {\mathrm{F}}_{\mathrm{c}}\mid$ are the observed and calculated structure factor amplitudes, respectively.

^cPer monomer in the asymmetric unit.

^dRefined lactate occupancy = 0.52.

^eRamachandran plot statistics calculated for nonproline and nonglycine residues using PROCHECK.⁴⁸