Primary structure of a constituent polypeptide chain of the chlorocruorin from Sabellastarte indica

• Published in: Biochimica et biophysica acta Vol. 1252; no. 2; pp. 189 - 193
• Main Authors: Suzuki, Tomohiko, Hirao, Yuriko, Vinogradov, Serge N.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.10.1995
• Subjects: Amino Acid Sequence; Animals; Base Sequence; cDNA sequence; Chlorocruorin; Hemeproteins - chemistry; Hemeproteins - isolation & purification; Hemoglobin; Hemoglobins - chemistry; Molecular Sequence Data; Peptide Fragments - chemistry; Polychaeta - chemistry; Polymerase Chain Reaction; Primary structure; Sabellastarte indica; Sequence Alignment; cDNA sequence; Hemoglobin; Primary structure; Chlorocruorin; Sabellastarte indica
• ISSN: 0167-4838; 0006-3002; 1879-2588
• DOI: 10.1016/0167-4838(95)00147-M

A 16 kDa polypeptide chain (chain E) was isolated from the giant extracellular chlorocruorin from the polychaete Sabellastarte indica by reverse-phase chromatography, and the N-terminal 19 amino-acid residues was determined by an automated protein sequencer. The cDNA of Sabellastarte chain E was amplified by polymerase chain reaction (PCR), and the complete nucleotide sequence of 1205 by was determined. The open reading frame is 498 nucleotides in length and encodes a protein with 165 amino-acid residues. Comparison of the cDNA-derived amino-acid sequence with the protein sequence shows that Sabellastarte chain E has a signal peptide of 16 residues at the N-terminus, the mature protein consisting of 149 amino-acid residues with a calculated molecular mass of 16636 Da. The amino-acid sequence of Sabellastarte chain E shows 42–49% sequence identity with the corresponding chains of the giant hemoglobins from Tylorrhynchus (polychaete, Annelida), Lumbricus (oligochaete, Annelida), Lamellibrachia (Vestimentifera) and Oligobrachia (Pogonophora). Thus, we conclude that chlorocruorin with chlorocruorohaem falls into the ‘hemoglobin/mygobin family’. This is the first complete sequence of a globin polypeptide chain of a chlorocruorin.