PDBsum entry: 1g7a

Hormone/growth factor

PDB id: 1g7a

Contents

Protein chains

21 a.a.

30 a.a. *

29 a.a. *

28 a.a. *

Ligands

ACN ×2

GOL

Metals

_CL ×7

_ZN ×7

Waters ×335

* Residue conservation analysis

PDB id:

1g7a

Name:

Hormone/growth factor

Title:

1.2 a structure of t3r3 human insulin at 100 k

Structure:

Insulin a-chain. Chain: a, c, e, g. Fragment: a-chain. Engineered: yes. Insulin b-chain. Chain: b, d, f, h. Fragment: b-chain. Engineered: yes

Source:

Synthetic: yes. Other_details: this sequence occurs naturally in homo sapie (human). (Human)

Biol. unit:

Dodecamer (from PDB file)

Resolution:

1.20Å R-factor: 0.169 R-free: 0.193

Authors:

G.D.Smith,W.A.Pangborn,R.H.Blessing

Key ref:

G.D.Smith et al. (2001). Phase changes in T(3)R(3)(f) human insulin: temperature or pressure induced? Acta Crystallogr D Biol Crystallogr, 57, 1091-1100. PubMed id: 11468392 DOI: 10.1107/S0907444901007685

Date:

09-Nov-00 Release date: 03-Aug-01

Protein chains

P01308  (INS_HUMAN) -  Insulin

Seq: 110 a.a.

Struc: 21 a.a.

Protein chains

P01308  (INS_HUMAN) -  Insulin

Seq: 110 a.a.

Struc: 30 a.a.

Protein chain

P01308  (INS_HUMAN) -  Insulin

Seq: 110 a.a.

Struc: 29 a.a.

Protein chain

P01308  (INS_HUMAN) -  Insulin

Seq: 110 a.a.

Struc: 28 a.a.

 Gene Ontology (GO) functional annotation 

• Cellular component: extracellular region (1 term)
• Biochemical function: hormone activity (1 term)

DOI no: 10.1107/S0907444901007685

Acta Crystallogr D Biol Crystallogr 57:1091-1100 (2001)

PubMed id: 11468392

Phase changes in T(3)R(3)(f) human insulin: temperature or pressure induced?

G.D.Smith, W.A.Pangborn, R.H.Blessing.

ABSTRACT

The structure of T(3)R(3) hexameric human insulin has been determined at 100 K from two different crystals at 1.2 and 1.3 A resolution and refined to residuals of 0.169 and 0.176, respectively. Owing to a phase change, the c axis is double its room-temperature value and the asymmetric unit contains two independent TR(f) insulin dimers. Compared with the orientation in the room-temperature structure, one dimer undergoes a rotation about the c axis of -5 degrees, while the second is rotated +4 degrees. A superposition of the backbone atoms of the two independent dimers shows that the C(alpha) atoms of five residues within the R(f)-state monomers are displaced by more than 1.0 A; smaller displacements are observed for the T-state monomers. Four zinc ions lie on the crystallographic threefold axis and each forms bonds to three symmetry-related HisB10 N(varepsilon2) atoms from the T- and R(f)-state trimers. While three of the zinc ions are tetrahedrally coordinated with a chloride ion completing the coordination sphere, mixed tetrahedral/octahedral coordination is observed for one of the T-state zinc ions. The three symmetry-related "phenolic binding sites" in one hexamer contain water molecules and a glycerol molecule, but the same sites in the second hexamer are occupied by a zinc ion coordinated to an alternate conformation of HisB10, a symmetry-related HisB5 and two chloride ions. Two additional and partially occupied zinc ion sites are observed at the interface between the two independent dimers. One zinc ion is coordinated by a T-state HisB5 of one dimer, an R-state HisB5 of the second dimer and two water molecules; the second zinc ion is coordinated by an alternate side-chain conformation of the T-state HisB5 and three water molecules. The carboxyl group of one GluB13 side chain, which exists in two discrete conformations, appears to be protonated, because short contacts exist to a second carboxyl group or to a carbonyl O atom.

Selected figure(s)

Figure 6.
Figure 6 SETOR drawing (Evans, 1993[Evans, S. V. (1993). J. Mol. Graph. 6, 244-245.]) of the interface between the two independent dimers, illustrating the coordination to the two zinc ions. A chains are colored red, B chains green, water molecules dark blue, zinc ions magenta, histidine side chains cyan and disulfide bridges yellow.

Figure 7.
Figure 7 Interactions between the GluB13 side chains in (a) 1trz; (b) hexamer 1 of the present study and (c) hexamer 2 of the present study. In (c), the side chains of SerB9.3 are colored cyan; the black dashed lines illustrate the 2.54 Å contact between GluB13.4 O 1 and GluB13.3 O 2 and the 2.73 Å contact between the carbonyl O of SerB9.3 and O 2 of the second alternate orientation of GluB13.4.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2001, 57, 1091-1100) copyright 2001.

Figures were selected by an automated process.