Tetrad or triad? insights from a versatile Fe(ii) structural and functional model of the 3-histidine 1-carboxylate tetrad in C–C bond cleaving dioxygenase enzymes
Fadul, Adam; Cundari, Thomas; Bertke, Jeffery; Toledo, Santiago A.; RSC Advances 16 (2026) 8695–8708; doi:10.1039/D5RA09716A

data_7251601
_publ_section_title
;
 Tetrad or triad? insights from a versatile Fe(ii) structural and
 functional model of the 3-histidine 1-carboxylate tetrad in C--C bond
 cleaving dioxygenase enzymes
;
_journal_issue                   10
_journal_name_full               'RSC Advances'
_journal_page_first              8695
_journal_page_last               8708
_journal_paper_doi               10.1039/D5RA09716A
_journal_volume                  16
_journal_year                    2026
_chemical_formula_moiety         'C42 H60 Fe2 N6 O3, 2(C F3 O3 S)'
_chemical_formula_sum            'C44 H60 F6 Fe2 N6 O9 S2'
_chemical_formula_weight         1106.80
_space_group_crystal_system      tetragonal
_space_group_IT_number           86
_space_group_name_Hall           '-P 4bc'
_space_group_name_H-M_alt        'P 42/n :2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     intrinsic
_audit_creation_method           SHELXL-2019/1
_audit_update_record
;
2025-12-13 deposited with the CCDC.	2026-02-04 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.4628(11)
_cell_length_b                   16.4628(11)
_cell_length_c                   22.7913(16)
_cell_measurement_reflns_used    9908
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      2.47
_cell_volume                     6177.0(7)
_computing_cell_refinement       'SAINT V8.37A (Bruker, 2005)'
_computing_data_collection       'APEX3 V2016.5-0 (Bruker, 2016)'
_computing_data_reduction
; 
SAINT V8.37A, XPREP v2014/2, SADABS V2016/2 (Bruker, 2016) 
;
_computing_molecular_graphics    'SHELXLE v932 (Hubschle, 2011)'
_computing_publication_material  'XCIF V2014-2 (Bruker, 2014)'
_computing_structure_refinement  'SHELXL-2019/1 (Sheldrick, 2019)'
_computing_structure_solution    'SHELX-2014-5 (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX DUO/ApexII CCD'
_diffrn_measurement_method       'profile data from \f and \w scans'
_diffrn_radiation_monochromator  'multilayer mirrors'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0638
_diffrn_reflns_av_unetI/netI     0.0248
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            89663
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.384
_diffrn_reflns_theta_min         1.964
_exptl_absorpt_coefficient_mu    0.603
_exptl_absorpt_correction_T_max  0.97387
_exptl_absorpt_correction_T_min  0.91205
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2016/2 (Bruker, 2016)'
_exptl_crystal_colour            purple
_exptl_crystal_density_diffrn    1.190
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2304
_exptl_crystal_size_max          0.292
_exptl_crystal_size_mid          0.098
_exptl_crystal_size_min          0.091
_refine_diff_density_max         0.321
_refine_diff_density_min         -0.270
_refine_diff_density_rms         0.058
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     390
_refine_ls_number_reflns         5674
_refine_ls_number_restraints     199
_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.0511
_refine_ls_R_factor_gt           0.0368
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0484P)^2^+6.0793P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0966
_refine_ls_wR_factor_ref         0.1037
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4542
_reflns_number_total             5674
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra09716a2.cif
_cod_data_source_block           25226_a_sq
_cod_original_cell_volume        6177.0(9)
_cod_original_sg_symbol_H-M      'P 42/n'
_cod_database_code               7251601
_shelx_shelxl_version_number     2019/1
_shelx_estimated_absorpt_t_min   0.844
_shelx_estimated_absorpt_t_max   0.947
_shelx_res_checksum              85361
_shelx_fab_checksum              10684