Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-5-5
pubmed:abstractText
The crystal structure of the ferric form of myoglobin from the mollusc Aplysia limacina has been refined at 1.6 A resolution, by restrained crystallographic refinement methods. The crystallographic R-factor is 0.19. The tertiary structure of the molecule conforms to the common globin fold, consisting of eight alpha-helices. The N-terminal helix A and helix G deviate significantly from linearity. The distal residue is recognized as Val63 (E7), which, however, does not contact the heme directly. Moreover the sixth (distal) co-ordination position of heme iron is not occupied by a water molecule at neutrality, i.e. below the acid-alkaline transition point of A. limacina myoglobin. The heme group sits in its crevice in the conventional orientation and no signs of heme isomerism are evident. The iron atom is 0.26 A out of the porphyrin plane, with a mean Fe-N (porphyrin) distance of 2.01 A. The co-ordination bond to the proximal histidine has a length of 2.05 A, and forms an angle of 4 degrees with the heme normal. A plane containing the imidazole ring of the proximal His intersects the heme at an angle of 29 degrees with the (porphyrin) 4N-2N direction. Inspection of the structure of pH 9.0 indicates that a hydroxyl ion is bound to the Fe sixth co-ordination position.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
205
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
529-44
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Aplysia limacina myoglobin. Crystallographic analysis at 1.6 A resolution.
pubmed:affiliation
Dipartimento di Genetica e Microbiologia, Università di Pavia, Italy.
pubmed:publicationType
Journal Article